Mounted structure, liquid droplet ejection head, liquid droplet ejection apparatus and manufacturing method

ABSTRACT

A method of manufacturing a device that has a semiconductor element includes: forming a first wiring on a first surface of a first member; forming a second wiring on a second surface of a second member with a gap from a connection terminal and a third wiring on an inclined plane of the second member, the second member being disposed on the first member so that the first and second surfaces face in the same direction, the third wiring being aligned with, and connecting, the first and second wirings; disposing the semiconductor element on the first or second surface; and providing plating that electrically connects the first, second and third wiring with the connection terminal, wherein the connection terminal faces the second wiring, and the plating is provided in the gap between the connection terminal and the second wiring.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No. 11/337,920filed Jan. 23, 2006, which claims priority to Japanese PatentApplication No. 2005-017951, filed Jan. 26, 2005, Japanese PatentApplication No. 2005-017952, filed Jan. 26, 2005, Japanese PatentApplication No. 2005-078974, filed Mar. 18, 2005, and Japanese PatentApplication No. 2005-309522, filed Oct. 25, 2005, the contents of whichare incorporated herein by reference.

BACKGROUND

1. Technical Field

The present invention relates to mounted structure, liquid dropletejection head, liquid droplet ejection apparatus, and manufacturingmethod thereof.

2. Related Art

A liquid droplet ejection method (ink jet method) is proposed for usewhen manufacturing an image forming device or micro device. The liquiddroplet ejection method is a method for forming a desired patternejected onto a substrate, in which a functional liquid which includes amaterial for forming the device or for forming the image is made intoliquid droplets and is ejected from the droplet ejection head.

In the liquid droplet ejection head (ink jet type recording head)disclosed in Japanese Unexamined Patent Application, First PublicationNo. 2000-127379, a wiring semiconductor element (driver IC) connectionterminal arranged on an upper part of a step difference, and a drivenelement (piezoelectric element) arranged on a lower part of the stepdifference are connected by wire bonding.

Using a liquid droplet ejection head, in a method which realizes animage forming device or micro device manufacture, in order to realizeminute detailing of a highly detailed image or micro device, the liquiddroplet ejection head nozzle aperture distance between nozzle apertures(nozzle pitch) should by made as small (narrow) as possible. Sincepiezoelectric elements are multiply formed corresponding to the nozzleapertures, if the nozzle pitch is made small, the distance between thepiezoelectric elements should also be small, corresponding to the nozzlepitch. If the distance between the piezoelectric elements is small,connection between the multiple piezoelectric elements, and between therespective wiring and the driver IC, by the wire bonding method isdifficult.

SUMMARY

An advantage of some aspects of the invention is to provide a structurecapable of mounting, even if the wiring has a narrow pitch semiconductorelement, a method of manufacture of a device, a liquid droplet ejectionhead and its method of manufacture.

A further object of some aspects of the invention is to provide a liquiddroplet ejection apparatus which has a liquid droplet ejection head.

A mounting structure according to an aspect of the invention includes: afirst member that has a first surface on which is formed a first wiring;a second member disposed on the first surface of the first member andhaving a second surface and a side surface, the second surface facing ina same direction as the first surface of the first member and on whichis formed a second wiring, the side surface on which is formed a thirdwiring that combines the first wiring and the second wiring; asemiconductor element disposed on the first surface of the first memberor on the second surface of the second member; and plating thatelectrically connects the first wiring, the second wiring, the thirdwiring, and a connection terminal of the semiconductor element.

In accordance with an embodiment of the invention, even if the wiringhas a narrow pitch, semiconductor element mounting is possible for wirebonding, without providing a space for a guide wire.

It is preferable that a configuration be adopted in which, the sidesurface of the second member is an inclined surface.

According to this configuration, in comparison with when the sidesurface of the second member is a vertical surface, third wiring can beeasily formed on the side surface of the second member.

It is preferable that a configuration be adopted in which, at least oneof the first wiring, the second wiring, and the third wiring is composedof a photosensitive resin mixed with a catalyst.

According to this configuration, patterning of wiring with onlyphotolithography is possible, simplifying the manufacturing process.Furthermore, plating is reliably provided by a catalyst.

A manufacturing method of a device that has a semiconductor element, themethod according to an aspect of the invention includes: forming a firstwiring on a first surface of a first member; forming a second wiring ona second surface of a second member and a third wiring on a side surfaceof the second member, the second member disposed on the first surface ofthe first member, the second surface facing in a same direction as thefirst surface of the first member, the third wiring combining the firstwiring and the second wiring; disposing the semiconductor element on thefirst surface of the first member or on the second surface of the secondmember; and providing plating that electrically connects the firstwiring, the second wiring, the third wiring, and a connection terminalof the semiconductor element.

In accordance with an embodiment of the invention, an electricalconnection is assured by plating even if there is mutual positionalslippage or a gap between the connection terminal and the wiring.Furthermore, simultaneous execution of mounting the semiconductorelement and the electrical connection of each wiring becomes possible,simplifying the manufacturing process.

A liquid droplet ejection head that ejects liquid droplets throughdeformation of a driven element, the head according to an aspect of theinvention includes: a first substrate having a pressurizing chamber witha nozzle aperture that ejects liquid droplets, and a first surface onwhich is formed a first wiring electrically connected to the driveelement; a second substrate disposed on the first surface of the firstsubstrate and covering the driven element, the second substrate having asecond surface and a side surface, the second surface facing in a samedirection as the first surface of the first substrate and on which isformed a second wiring, the side surface on which is formed a thirdwiring that combines the first wiring and the second wiring; asemiconductor element disposed on the second surface of the secondsubstrate, and which drives the driven element; and plating thatelectrically connects the first wiring, the second wiring, the thirdwiring, and a connection terminal of the semiconductor element.

In accordance with an embodiment of the invention, in conjunction withthe narrow pitching of the nozzle aperture, even if the first wiring hasa narrow pitch, the semiconductor element can be mounted withoutproviding a space for a guide wire for wire bonding.

It is preferable that a configuration be adopted in which, the secondsubstrate is a silicon substrate having a <100> orientation, and theside surface of the second substrate is an inclined surface formed byetching the silicon substrate.

According to this configuration, an inclined surface can be easilyformed.

It is preferable that a configuration be adopted in which, at least oneof the first wiring, the second wiring, and the third wiring is composedof a photosensitive resin mixed with a catalyst.

According to this configuration, patterning of the wiring with onlyphotolithography is possible, simplifying the manufacturing process.Furthermore, plating is reliably provided by the catalyst.

It is preferable that a configuration be adopted in which, a part of thesecond wiring is arranged facing the connection terminal of thesemiconductor element, and the connection terminal of the semiconductorelement is provided with a conductive protrusion that protrudes andfaces the second wiring.

According to this configuration, by the protrusion of the semiconductorelement, the semiconductor element and the second wiring can be reliablycombined by means of plating, enabling improved reliability of theelectrical connection.

A manufacturing method of a liquid droplet ejection head that ejectsliquid droplets through deformation of a driven element, the methodaccording to an aspect of the invention includes: forming a first wiringon a first surface of a first substrate that has a pressurizing chamberwith a nozzle aperture that ejects liquid droplets; forming a secondwiring on a second surface of a second substrate and a third wiring on aside surface of the second substrate, the second substrate disposed onthe first surface of the first substrate, the second surface facing in asame direction as the first surface of the first substrate, the thirdwiring combining the first wiring and the second wiring; disposing thesemiconductor element on the second surface of the second substrate; andproviding plating that electrically connects the first wiring, thesecond wiring, the third wiring, and a connection terminal of thesemiconductor element.

In accordance with an embodiment of the invention, even if there ispositional slippage or a gap between the connection terminal and thewiring or among the wiring, an electrical connection can be secured bymeans of the plating, making it possible to mount the semiconductorelement and electrical connection of each wiring, simplifying themanufacturing process.

A mounting structure according to an aspect of the invention includes: astepped body having an upper step surface, a lower step surface, and aside surface that combines the upper step surface and the lower stepsurface, a first wiring formed on the lower step surface of the steppedbody, a second wiring formed on the upper step surface of the steppedbody, a semiconductor element disposed on the side surface of thestepped body, and plating that electrically connects the first wiring,the second wiring, and a connection terminal of the semiconductorelement.

In accordance with an embodiment of the invention, even if the wiring ismade to be a narrow pitch, mounting the semiconductor element can beaccomplished without providing a wire guide space for wire bonding.

It is preferable that a configuration be adopted in which, the sidesurface of the stepped body is an inclined surface.

According to this configuration, the semiconductor device can be easilymounted in comparison with when the side surface of the stepped body isa vertical surface.

It is preferable that a configuration be adopted in which, at least oneof the first wiring, the second wiring, and the third wiring is composedof a photosensitive resin mixed with a catalyst.

According to this configuration, patterning of the wiring only withphotolithography is possible, simplifying the manufacturing process.Furthermore, plating is reliably provided by the catalyst.

A manufacturing method of a device that has a semiconductor element, themethod according to an aspect of the invention includes: forming a firstwiring on a lower step surface of a stepped body, forming a secondwiring on an upper step surface of the stepped body, disposing thesemiconductor element on a side surface that combines the upper stepsurface and the lower step surface of the stepped body, and providingplating that electrically connects the first wiring, the second wiring,and a connection terminal of the semiconductor element.

In accordance with an embodiment of the invention, even if slippagebetween each wiring and the electrical connection of the semiconductorelement is caused by a manufacturing error or the like, the electricalconnection can be secured by plating. Furthermore, there is no need toform wiring on the side surface of the stepped body, simplifying themanufacturing process.

A liquid droplet ejection head that ejects liquid droplets throughdeformation of a driven element, the head according to an aspect of theinvention includes: a first substrate having a pressurizing chamber witha nozzle aperture that ejects liquid droplets, and a first surface onwhich is formed a first wiring electrically connected to the drivenelement; a second substrate disposed on the first surface of the firstsubstrate and covering the driven element, the second substrate having asecond surface and a side surface, the second surface facing in a samedirection as the first surface of the first substrate and on which isformed a second wiring, the side surface on which is formed a thirdwiring that combines the first wiring and the second wiring; asemiconductor element disposed on the side surface of the secondsubstrate, and which drives the driven element; and plating thatelectrically connects the first wiring, the second wiring, the thirdwiring, and a connection terminal of the semiconductor element.

In accordance with an embodiment of the invention, in conjunction withthe narrow pitching of the nozzle aperture, even if the first wiringelectrically connected to the drive element is made to be a narrowpitch, the semiconductor element can be mounted without providing a wireguide space for wire bonding.

It is preferable that a configuration be adopted in which, the secondsubstrate is a silicon substrate having a <100> orientation, and theside surface of the second substrate is an inclined surface formed byetching the silicon substrate.

According to this configuration, the inclined surface can be simplyformed. Furthermore, the semiconductor element can be easily mounted onthe side surface of the protective substrate.

It is preferable that a configuration be adapted in which, at least oneof the first wiring, the second wiring, and the third wiring is composedof a photosensitive resin mixed with a catalyst.

According to this configuration, patterning of the wiring becomespossible with only photolithography, simplifying the manufacturingprocess. Furthermore, plating is reliably provided.

A manufacturing method of a liquid droplet ejection head that ejectsliquid droplets through deformation of a driven element, the methodaccording to an aspect of the invention includes: forming a first wiringon a first surface of a first substrate that has a pressurizing chamberwith a nozzle aperture that ejects liquid droplets; forming a secondwiring on a second surface of a second substrate and a third wiring on aside surface of the second substrate, the second substrate disposed onthe first surface of the first substrate, the second surface facing in asame direction as the first surface of the first substrate, the thirdwiring combining the first wiring and the second wiring; disposing thesemiconductor element on the side surface of the second substrate; andproviding plating that electrically connects the first wiring, thesecond wiring, the third wiring, and a connection terminal of thesemiconductor element.

In accordance with an embodiment of the invention, even if positionalslippage between each of the wiring and the connection terminal of thesemiconductor element is caused by a manufacturing error or the like, anelectrical connection can be positively secured by plating, simplifyingthe manufacturing process without forming wiring on the side surface ofthe protective substrate.

A mounting structure according to an aspect of the invention includes: afirst member that has a first surface on which is formed a first wiring;a second member disposed on the first surface of the first member andhaving a second surface, a third surface and a side surface, the secondsurface facing in a same direction as the first surface of the firstmember and on which is formed a second wiring, the third surface beingadjacent to the first member and on which is formed a third wiring, theside surface on which is formed a forth wiring that combines the secondwiring and the third wiring; a semiconductor element disposed on thesecond surface of the second member; and plating that electricallyconnects the first wiring, the second wiring, the third wiring, theforth wiring, and a connection terminal of the semiconductor element.

In accordance with an embodiment of the invention, even if the wiring ismade to be a narrow pitch, the semiconductor can be mounted withoutproviding a wire guide for wire bonding. Furthermore, it is sufficientif only plating of the second member is provided, and the influence ofplating processing on the first member can be avoided. Furthermore,improved electrical reliability of the mounting construction can beachieved.

It is preferable that a configuration be adapted in which, the sidesurface of the second member is an inclined surface.

According to this configuration, forming the wiring on the side surfaceof the second member is easy in comparison to when the side surface ofthe second member is a vertical surface.

It is preferable that a configuration be adapted in which, at least oneof the first wiring, the second wiring, the third wiring, and the forthwiring is composed of a photosensitive resin mixed with a catalyst.

According to this configuration, patterning of each wiring is possibleusing only photolithography, thereby simplifying the manufacturingprocess. Furthermore, plating can be reliably provided by means of acatalyst.

It is preferable that a configuration be adapted in which, the sidesurface of the second member has multiple inclined surfaces of mutuallydifferent angles relative to the second surface.

According to this configuration, exposure of the side surface of thesecond membrane may be accomplished by dividing one side from the otherside, and in comparison with exposing the entire side surface body once,adjustment of the focal point depth of the exposure device is easy.Furthermore, forming the wiring on the side surface of the second membercan be simply accomplished at low-cost.

It is preferable that a configuration be adapted in which, the sidesurface of the second member has multiple inclined surfaces in which amutually narrow angle is obtuse, or a curved surface.

According to this configuration, each wiring can be formed continuously,and applied to another surface from one surface of the second member.Furthermore, even when a gap occurs between each wiring, a conductiveconnection can be positively realized between each wiring by means ofplating grown from the closely proximate wiring. Furthermore, improvedelectrical reliability of the mounting construction can be achieved.

A manufacturing method of a device that has a semiconductor element, themethod according to an aspect of the invention includes: forming a firstwiring on a first surface of a first member; forming a second wiring ona second surface of a second member, a third wiring on a third surfaceof the second member, and a forth wiring on a side surface of the secondmember, the third surface being opposite the second surface; disposingthe semiconductor element on the second surface of the second member;providing plating that electrically connects the second wiring, thethird wiring, the forth wiring and a connection terminal of thesemiconductor element; and disposing the second member on the firstsurface of the first member to electrically connect the plating and thefirst wiring.

In accordance with an embodiment of the invention, even if there ispositional slippage or a gap between the connection terminal and thewiring or mutually between the wiring, a secure conductive connection isrealized between the wiring by means of plating grown from the proximatewiring. Furthermore, the electrical reliability of the mountingconstruction can be improved.

A liquid droplet ejection head that ejects liquid droplets throughdeformation of a driven element, the head according to an aspect of theinvention includes: a first substrate having a pressurizing chamber witha nozzle aperture that ejects liquid droplets, and a first surface onwhich is formed a first wiring electrically connected to the drivenelement; a second substrate disposed on the first surface of the firstsubstrate and covering the driven element, the second substrate having asecond surface, a third surface and a side surface, the second surfacefacing in a same direction as the first surface of the first substrateand on which is formed a second wiring, the third surface contacting thefirst surface of the first substrate and on which is formed a thirdwiring, the side surface on which is formed a third wiring that combinesthe second wiring and the third wiring; a semiconductor element disposedon the second surface of the second substrate, and which drives thedriven element; and plating that electrically connects the first wiring,the second wiring, the third wiring, the forth wiring, and a connectionterminal of the semiconductor element.

In accordance with an embodiment of the invention, in conjunction withmaking the nozzle aperture to be a narrow pitch, even if the fourthwiring conductively connected to the drive element is made to be anarrow pitch, the semiconductor element can be mounted without providinga wire guide space for wire bonding. Furthermore, it is sufficient ifplating is provided on only the protective substrate, and the influenceof the plating process on the drive element requiring high precision canbe avoided. Furthermore, the electrical reliability of the dropletejection head can be improved.

It is preferable that a configuration be adapted in which, the secondsubstrate is a silicon substrate having a <100> orientation, and theside surface of the second substrate is an inclined surface formed byetching the silicon substrate.

According to this configuration, the inclined surface can be simplyformed. Furthermore, formation can be easily accomplished of the wiringon the side surface of the protective substrate.

It is preferable that a configuration be adapted in which, at least oneof the first wiring, the second wiring, the third wiring and the fourthwiring is composed of a photosensitive resin mixed with a catalyst.

According to this configuration, it is possible for patterning of wiringto be realized using only photolithography, simplifying themanufacturing process. Furthermore, the plating can be positivelyprovided by the catalyst.

It is preferable that a configuration be adapted in which, the sidesurface of the second substrate has multiple inclined surfaces ofmutually different angles relative to the second surface.

According to this configuration, exposure of the side surface of theprotective substrate may be realized by dividing one side from the otherside, and in comparison with exposing the entire side surface body once,adjustment of the focal point depth of the exposure device is easy.Furthermore, the wiring can be simply formed at low-cost.

It is preferable that a configuration be adapted in which, the sidesurface of the second substrate has multiple inclined surfaces in whicha mutually narrow angle is obtuse, or a curved surface.

According to this configuration, each wiring can be formed continuously,and applied to another surface from one surface of the protectivesubstrate. Furthermore, even when a gap occurs between each wiring, aconductive connection can be positively realized between each wiring bymeans of plating grown from the closely proximate wiring.

It is preferable that a configuration be adapted in which, the platingand the first wiring are electrically connected via an anisotropicconductive film.

According to this configuration, even if the first wiring is made to bea narrow pitch, the first wiring and plating can be positivelyelectrically connected through the oriented conductive film.

It is preferable that a configuration be adapted in which, thesemiconductor element is sealed.

According to this configuration, the semiconductor element can beprotected in the manufacturing process of a liquid droplet ejectionhead. Furthermore, the semiconductor element can be protected even afterthe completion of the liquid droplet ejection head.

A manufacturing method of a liquid droplet ejection head that ejectsliquid droplets through deformation of a driven element, the methodaccording to an aspect of the invention includes: forming a first wiringon a first surface of a first substrate that has a pressurizing chamberwith a nozzle aperture that ejects liquid droplets; forming a secondwiring on a second surface of a second substrate, a third wiring on athird surface of the second substrate, and a forth wiring on a sidesurface of the second substrate, the third surface being opposite thesecond surface; disposing the semiconductor element on the secondsurface of the second substrate; providing plating that electricallyconnects the second wiring, the third wiring, the forth wiring and aconnection terminal of the semiconductor element; and disposing thesecond substrate on the first surface of the first substrate to coverthe driven element and to electrically connect the plating and the firstwiring.

In accordance with an embodiment of the invention, even if there ispositional slippage or a gap between the connection terminal and thewiring or among the wiring, an electrical connection can be secure bymeans of the plating. Furthermore, it is possible to mount thesemiconductor element on the protective substrate and to simultaneouslyexecute the electrical connection of each wiring, simplifying themanufacturing process.

A liquid droplet ejection apparatus according to an aspect of theinvention has a liquid droplet ejection head described above.

In accordance with an embodiment of the invention, since the nozzleaperture is provided with a narrow pitch liquid droplet ejection head,it is possible to draw a pattern with high precision.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a liquid droplet ejection headaccording to the first embodiment.

FIG. 2 is a perspective view showing the liquid droplet ejection head isviewed from the lower side.

FIG. 3 is a cross-sectional view along the line A-A of FIG. 1.

FIG. 4 is a partially enlarged view showing the mounting constructionaccording to the first embodiment.

FIG. 5 is a flowchart diagram showing the manufacturing method of aliquid droplet ejection head.

FIGS. 6A, 6B, 6C, 6D, and 6E are cross-sectional process diagramsshowing the construction method of a liquid droplet ejection head.

FIG. 7 is a partially enlarged view showing a mounting constructionaccording to the second embodiment.

FIGS. 8A and 8B are a cross-sectional process diagrams showing theconstruction method of a liquid droplet ejection head.

FIG. 9 is a perspective view showing a liquid droplet ejection headaccording to the third embodiment.

FIG. 10 is a perspective view showing the liquid droplet ejection headfrom the lower side.

FIG. 11 is a cross-sectional view along the line A-A of FIG. 9.

FIG. 12 is a partially enlarged view showing the mounting structureaccording to the third embodiment.

FIG. 13 is a flowchart showing the method of manufacture of the liquiddroplet ejection head.

FIGS. 14A, 14B, 14C, 14D, and 14E are cross-sectional process diagramsshowing the manufacturing method of the liquid droplet ejection head.

FIG. 15 is a perspective view showing a liquid droplet ejection headaccording to the fourth embodiment.

FIG. 16 is a perspective view showing the liquid droplet ejection headviewed from the lower side.

FIG. 17 is a cross-sectional diagram along the line A-A of FIG. 15.

FIG. 18 is a partially enlarged view showing a mounting structureaccording to the fourth embodiment.

FIG. 19 is a flowchart of the method of manufacture of the liquiddroplet ejection head.

FIGS. 20A, 20B, 20C, 20D, 20E, 20F, and 20G are cross-sectional processdiagrams showing the method of manufacture of the liquid ejection head.

FIG. 21A is a partially enlarged view showing a liquid droplet ejectionhead according to the fifth embodiment.

FIG. 21B is a partially enlarged view showing the first deformationexample of the liquid droplet ejection head of the fifth embodiment.

FIG. 21C is a partially enlarged view showing the second deformationexample of the liquid droplet ejection head of the fifth embodiment.

FIGS. 22A, 22B, 22C, and 22D are construction processes of the liquiddroplet ejection head according to the first deformation example of thefifth embodiment.

FIG. 23 is a perspective view showing an inkjet type recording deviceincluding an example of a liquid droplet ejection device.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

An explanation of the embodiments of the present invention is providedhereafter, with reference to the drawings. In the following explanation,an intersecting XYZ coordinate system is established, with reference towhich an explanation is provided according to the position of eachmember. A specific direction on a level plane is made to be the X-axisdirection, the intersecting direction on the same plane of which is theY-axis direction, and the respectively intersecting directions (namelythe vertical direction) in the X-axis direction and the Y-axis directionare made to be the Z-axis direction.

First Embodiment

An explanation of a first Embodiment of a liquid droplet ejection headaccording to the present invention is described hereafter with referenceFIGS. 1 to 3. FIG. 1 is a perspective view of an embodiment of theliquid droplet ejection head, FIG. 2 is a partially fragmented diagramof a perspective view in which the liquid droplet ejection head isviewed from below, and FIG. 3 is a cross-sectional diagram of line A-A,in FIG. 1.

As shown in FIG. 3, a liquid droplet ejection head 1 of the presentEmbodiment turns functional fluid into droplets, and ejects them from anozzle. The liquid droplet ejection head 1 is provided with a flow pathforming substrate (first member, first substrate) 10, a pressurizingchamber 12 which communicates with a nozzle aperture 15 from which theliquid droplets are ejected, and a piezoelectric element (drivenelement) 300 which produces a pressure change in the pressurizingchamber 12 arranged on the upper surface of the pressurizing chamber 12,and a reservoir forming substrate (protective substrate, second member,second substrate) 20 which covers the piezoelectric element 300 arrangedon the upper surface of the pressurizing chamber 20, and a semiconductorelement 200 which drives the piezoelectric element 300 arranged on theupper surface of the reservoir forming substrate 20. The operation ofthe liquid droplet ejection head 1 is controlled by an un-shown externalcontroller connected to the semiconductor element 200.

As shown in FIG. 2, on the lower side (−Z side) of the liquid dropletejection head 1 is mounted a nozzle substrate 16. On the nozzlesubstrate 16 are arranged multiple nozzle apertures 15 which ejectliquid droplets, and which are arranged in the Y-axis direction. In thisembodiment, groups of nozzle apertures 15 arranged in multiple regionson the nozzle substrate 16 are respectively designated as a first nozzleaperture group 15A, a second nozzle aperture group 15B, a third nozzleaperture group 15C, and a fourth nozzle aperture group 15D.

The first nozzle aperture group 15A and the second nozzle aperture group15B are arranged in a row in the X-axis direction. The third nozzleaperture group 15C is provided on the first nozzle aperture group 15A+Yside, and the fourth nozzle aperture group 15D is provided on the nozzleaperture group 15B+Y side. The third nozzle aperture group 15C and thefourth nozzle aperture group 15D are arranged in a row in the X-axisdirection.

FIG. 2 shows a construction in which each nozzle aperture group 15A-15Dis respectively composed of a six-unit nozzle aperture 15. However, eachnozzle aperture group is actually composed, for example, of a 20-unitnozzle aperture 15.

The flow path forming substrate 10 is arranged on the upper side (+Zside) of the nozzle substrate 16, in which the lower surface of the flowpath forming substrate 10 and the nozzle substrate 16 are fixed by anadhesive or a thermal deposition film, or the like. The flow pathforming substrate 10 may be composed of silicon, glass, or ceramicmaterial or the like, and in the present embodiment is formed ofsilicon. On the underside of the flow path forming substrate 10 areformed multiple partition walls 11 extending from the center in theX-axis direction, by the partial removal of a silicon single crystallinesubstrate including a welding base material of the flow path formingsubstrate 10 by means of anisotropic etching. By means of partitionwalls 11, multiple regions having a comb-shape are formed in thecompartments on the flow path forming substrate 10. Among these apertureregions, components are formed to extend in the X-axis direction of thepressurizing chamber (first member) 12 enclosed by the nozzle substrate16 and an oscillating plate 400. The pressurizing chamber 12 houses afunctional liquid, which is ejected from the nozzle apertures 15 bymeans of the pressure applied when operating the liquid droplet ejectionhead 1.

Each pressurizing chamber 12 is provided corresponding to multiplenozzle apertures 15. In other words, the pressurizing chamber 12 isprovided in multiple rows in the Y-axis direction so as to correspond tothe multiple apertures 15 respectively composing the first throughfourth nozzle aperture groups 15A-15D. The multiply formed pressurizingchambers 12 corresponding to the first nozzle aperture group 15A composea first pressurizing chamber group 12A, the pressurizing chambers 12multiply formed corresponding to the second nozzle aperture group 15Bcompose a second pressurizing chamber group 12B, the pressurizingchambers 12 multiply formed corresponding to the third nozzle aperturegroup 15C compose a third pressurizing chamber group 12C, and thepressurizing chambers 12 multiply formed corresponding to the fourthaperture group 15D compose a fourth pressurizing chamber group 12D. Thefirst pressurizing chamber group 12A and the second pressurizing chambergroup 12B are arranged in rows in the X-axis direction, in between whichare formed partition walls 10K extending in the Y-axis direction. In thesame manner, the third pressurizing chamber group 12C and the fourthpressurizing chamber group 12D are arranged in rows extending in theX-axis direction, between which are also formed partition walls 10K.

Furthermore, among the com-shape aperture regions formed on the flowpath substrate 10, the part formed to extend in the Y-axis directionshown in the drawing composes a reservoir 100. The end of a substrateexternal margin side (+X side) in the multiple pressurizing chambers 12which forms the first pressurizing chamber group 12A is connected to thereservoir 100, which holds the functional liquid supplied to thepressurizing chamber 12 in reserve, and becomes a common functionalliquid preservation chamber (ink chamber) of the multiple pressurizingchambers 12 composing the first pressurizing chamber group 12A. In therespective second, third and fourth pressurizing chamber groups 12B,12C, and 12D as well, the reservoir 100 is connected in the same manneras indicated above, and composes a temporary functional liquidaccumulation unit which is supplied to the respective pressurizinggroups 12B to 12D.

As shown in FIG. 3, the reservoir 100 has a reservoir portion 21 formedon the reservoir formed substrate 20, and is composed from a coupledpart formed in the current flow formed substrate 10. The coupling part13 has a function for connecting the reservoir portion 21 to each of therespective pressurizing chambers 12. On the outside (opposite side tothe flow path forming substrate 10) of the reservoir forming substrate20 is connected a compliance substrate 30 constructed of a laminatedlayer including a sealing film 31 and a fixed plate 32. In thecompliance substrate 30, the sealing film 31 arranged internally isformed from a material (for example, polyphenylene sulfide film having athickness of approximately 6 μm) having elasticity characteristics oflow rigidity. On the other hand, the fixed plate 32 arranged on theoutside is formed from material (for example, stainless steel having athickness of 30 μm), a hard metalic.

In the fixed plate 32 is formed an aperture 33 formed by cutting out theplane surface region corresponding to the reservoir 100. With such astructure, the upper part of the reservoir 100 seals only the elasticsealing film 31, and forms a deformable elastic part 22 by changing theinternal pressure. Furthermore, in the compliance substrate 30, isformed a functional liquid introduction aperture 25 for supplyingfunctional liquid to the reservoir 100. In the reservoir formingsubstrate 20 is provided an introduction path 26 which communicates withthe functional liquid introduction aperture 25 and the reservoir 100.

Functional liquid introduced from the functional liquid introductionaperture 25 flows into the reservoir 100 through the introduction path26, and is supplied to the multiple pressurizing chambers 12 composingthe first pressurizing chamber group 12A, through a supply path 14.Pressure changes are generated in the reservoir 100 by the flow of thefunctional liquid or by heating the periphery when driving thepiezoelectric element 300. However, since a flexible part 22 of thereservoir 100 absorbs the pressure changes produced by elasticdeformation, the inside of the reservoir 100 ordinarily remains fixed.

On the upper surface side (+Z side) of the flow path forming substrate10 shown in the drawing, is arranged an oscillation plate 400. Theoscillation plate 400 has a construction which laminates a flexible film50 and a lower electrode film 60 chronologically from the flow pathforming substrate 10 side. The flexible film 50 arranged on the flowpath forming substrate 10 side is formed, for example, from a siliconoxide film having a thickness of approximately 1-2 μm. The lowerelectrode film 60 is formed, for example, from a metallic film having athickness of approximately 0.2 μm. In the embodiment, the lowerelectrode film 60 functions as a common electrode of multiplepiezoelectric elements 300 arranged between the flow path formingsubstrate 10 and the reservoir forming substrate 20.

On the upper surface side (+Z side) of the oscillation plate shown inthe drawing is arranged the piezoelectric element 300 for deforming theoscillation plate 400. The piezoelectric element 300 has a structure inwhich a piezoelectric film 70 and an upper electrode film 80 arelaminated from the lower electrode film 60 side. The piezoelectric film70 is formed, for example, from a PZT film or the like having athickness of approximately 1 μm. The electrode film 80 is formed, forexample, from a metallic film having a thickness of approximately 0.1μm. As a summary of the piezoelectric element 300, in addition to thepiezoelectric film 70 and the upper electrode film 80, the lowerelectrode 60 may also be included. The lower electrode film 60 functionsas the oscillation plate piezoelectric element 300, and also functionsas an oscillation plate 400. In the embodiment, the flexible film 50 andlower electrode film 60 adopt a structure which functions as theoscillation plate 400. However, by eliminating the flexible film 50, thelower electrode film 60 may also be composed to jointly serve as theflexible film 50.

The piezoelectric element 300 (the piezoelectric film 70 and upperelectrode film 80) is multiply provided so as to correspond to themultiple nozzle apertures 15 and the pressurizing chambers 12. In theembodiment, a group of piezoelectric elements 300 provided in multiplerows in the Y-axis direction so as to respectively correspond to thenozzle apertures 15 composing the first nozzle aperture group 15A aremade to be a so-called second piezoelectric element group. Furthermore,a first piezoelectric element group corresponding to the third nozzleaperture group is referred to as a third piezoelectric element group,and the first piezoelectric element group corresponding to the fourthnozzle aperture group is referred to as the fourth piezoelectric elementgroup. The first piezoelectric element group and a second piezoelectricelement group are arranged in rows in the X-axis direction. In the samemanner, the third piezoelectric element group and the fourthpiezoelectric element group are arranged in rows in the X-axisdirection.

In order to cover the piezoelectric element 300, the reservoir formingsubstrate (protective substrate, second member, second substrate) 20 isarranged on the upper surface side (+Z side) of the flow path formingsubstrate 10 shown in the drawing. Since the reservoir forming substrate20, in addition to the flow path forming substrate 10, is a member whichforms the base of the liquid droplet ejection head 1, it is desirablethat, as its structural member, use be made of a rigid material whichhas roughly the same thermal expansion ratio as that of the flow pathforming substrate 10. In the case of the embodiment, since the flow pathforming substrate 10 is formed from silicon, optimal use is made of asilicon single crystal substrate of the same material. Since the siliconsubstrate easily realizes high precision processing by means ofanisotropic etching, there is the advantage that a piezoelectric elementsupport 24, described hereafter, can be easily formed. As with the flowpath forming substrate 10, it is also possible to compose a reservoirforming substrate 20, by using glass or ceramic material or the like.

On the reservoir forming substrate 20 is provided a seal 23 whichtightly seals the piezoelectric element 300. In the embodiment, the partwhich seals the first piezoelectric element group is made to be a firstseal 23A, and the part which seals a second piezoelectric element groupis made to be the second seal 23B. In the same manner, the part whichseals the third piezoelectric element group is made to be a third seal,and the part which seals the fourth piezoelectric element group is madeto be the fourth seal. The third seal is provided with a piezoelectricelement support (element support) 24 formed from an indentation of aplane surface viewed as being approximately rectangular and extendingvertically from the page surface of FIG. 3. The piezoelectric elementsupport 24, in addition to assuring that there is no obstacle and thatthere is sufficient space on its periphery to permit movement of thepiezoelectric element 300, also has the function of tightly sealing thespace. The piezoelectric element support 24 has measurements whichenable sealing of at least the piezoelectric film 70 of thepiezoelectric element 300. Furthermore, the piezoelectric elementsupport 24 may also be partitioned for multiple piezoelectric elements300.

In this manner, the reservoir forming substrate 20 functions as aprotective substrate that shields the piezoelectric element 300 from theexternal environment.

With the reservoir forming substrate 20, by sealing the piezoelectricelement 300, deterioration of the piezoelectric element 300 caused byexternal aqueous components and the like can be prevented. Furthermore,with the present embodiment, the inside of the piezoelectric elementsupport 24 is sealed, but by creating an internal vacuum or anenvironment of nitrogen or argon within the piezoelectric elementsupport 24, it can be maintained at low humidity. By such aconstruction, deterioration of the piezoelectric element 300 can beeffectively prevented.

In the reservoir forming substrate 20, a groove 20 a is provided whichpenetrates the reservoir forming substrate 20 between the first seal 23Aand the second seal 23B in the reservoir forming substrate 20. Throughthe groove 20 a, the upper surface of the flow path forming substrate 10is exposed to the outside. Steps are formed from the upper surface ofthe exposed flow path substrate 10 to the upper surface of the seal 23of the reservoir forming substrate 20.

A side surface 20 b of the groove 20 a of the reservoir formingsubstrate 20 is an inclined surface. Particularly, if the reservoirforming substrate 20 is composed of a silicon substrate having a <1, 0,0> orientation, and if the silicon substrate is wet etched with analkali solution of KOH and the like, through differences in the etchingrate of each surface direction, the side surface 20 b of the groove 20 ais made to be an inclined surface of approximately 54°.

Among the piezoelectric elements 300 sealed by the piezoelectric elementsupport 24 of the reservoir substrate 20, the end of the −X side of theupper electrode film 80 extends to the upper surface of the exposed flowpath forming substrate 10, thereby composing a first wiring 36. Thefirst wiring 36 is composed of a metallic material including Al or Ni-Cr, Cu, Ni, Au, and Ag and the like. The first wiring 36 may also beaccomplished with a photosensitive resin material mixed with a catalyst.When the lower electrode film 60 is arranged in a planar sheet state onthe flow path forming substrate 10, an insulation film 600 is arrangedfor preventing short-circuiting between the upper electrode film 80extending to the outside of the piezoelectric element support 24 and thelower electrode film 60. Furthermore, in lieu of extending the upperelectrode film 80 in its existent state, the electrode wiringelectrically connected to the upper electrode film 80 is formed on theflow path forming substrate 10, and the electrode wiring may also bedrawn to the outside of the piezoelectric element support 24 and used asthe first wiring 36.

The second wiring 34 is formed on the upper surface of the reservoirforming substrate 20, and the third wiring 35 is formed on the sidesurface of the reservoir forming substrate 20. As shown in FIG. 1, thefirst wiring 36 and the same number of second wiring 34 and the thirdwiring 35 are formed in the same Y-directional position as the firstwiring 36. and coupling is accomplished between the second wiring 34 andthe third wiring 35. However, a gap of approximately several μm-10 μmmay also be formed.

The second wiring 34 and the third wiring 35 shown in FIG. 3, shoulddesirably be structured with a resin material mixed with a catalyst.Specifically, particles of Pd (palladium) are dispersed composed of aphotosensitive resin material. In this case, it is possible for thesecond wiring 34, and the third wiring 35 to be formed by means ofphotolithography. In other words, the resin material is coated on theupper surface and the side surface of the reservoir forming substrate20, and patterning can be accomplished of the second wiring 34 and thethird wiring 35 by exposure and development.

The second wiring 34 and the third wiring 35 may also be constructedwith a metallic material composed of Al or Ni—Cr, Cu, Ni, Au, and Ag.However, in patterning the metallic material, it is necessary for aresist to be subjected to masked etching, complicating the manufacturingprocess. In this regard, with a structure using a photosensitive resinmaterial mixed with a catalyst, the second wiring 34 and the thirdwiring 35 can be patterned using only photolithography, simplifying themanufacturing process.

On the upper surface side (+Z side) of the reservoir forming substrate20 shown in the drawing, the semiconductor element 200 is arranged facedown. The semiconductor element 200 includes, for example, asemiconductor integrated circuit (IC) which includes a circuit substrateor a drive circuit. As shown in FIG. 1, the present embodiment arrangesfour semiconductor elements 200A-200D to drive the first through fourthpiezoelectric element groups.

Furthermore, in the margin of the lower surface side (−Z side) of thesemiconductor element 200 shown in the drawing, are provided multipleconnection terminals 44, composed of a metallic material of Al or Ni—Cr,Cu, Ni, Au, and Ag and the like. At the end of the −X side of thesemiconductor element 200A are arranged the same number of connectionterminals 44 as for the second wiring 34, arranged in a row at the samepitch as the second wiring 34. Furthermore, at the end of thesemiconductor terminal 200A+X side is formed a connection terminal 44which is electrically connected to an external controller. By adjustingthe amount of adhesive arranged on the lower surface of thesemiconductor element 200 and the amount of heat/pressure applied whenadhering, a gap of approximately several μm-10 μm is formed between theconnection terminals 44 and the second wiring 34.

In this manner, a gap is provided between the connection terminal 44 andthe second wiring 34. Furthermore, since fixing is accomplished betweenthe reservoir forming substrate 20 and the flow path forming substrate10 through an (un-shown) adhesive, a gap is also provided between thethird wiring 35 and the first wiring 36. Furthermore, the resin materialmixed with a catalyst and which composes the second wiring 34 and thethird wiring 35 is an electrical insulating material, in which state thesemiconductor element 200 and the piezoelectric element 300 are notelectrically connected.

Plating 46 is provided on the surface of the first-third wiring and theconnection terminal. Specifically, plating 36 a is provided on thesurface of the first wiring 36, plating 35 a is provided on the surfaceof the third wiring 35, plating 34 a is provided on the surface of thesecond wiring 34, and plating 44 a is a provided on the surface of theconnection terminal 44. With the second wiring 34 and the third wiring35 composed of a resin material mixed with a catalyst, the plating 34 aand the plating 35 a are provided relative to the catalyst. The plating46 are composed of a metallic material such as Cu, or Ni, and the Au andthe like. Plating may also be mixed by different materials on thesurface of each wiring and connection terminal.

FIG. 4 is an explanatory diagram of the mounting structure according tothe first embodiment, and is an enlarged view of section B of FIG. 6E.As shown in FIG. 4, plating 44 a is provided on the surface of theconnection terminal 44 of the semiconductor element 200, and plating 34a is provided on the surface of the second wiring 34. By combining thegrown plating 44 a and 34 a, the connection terminal 44 and the secondwiring 34 are electrically connected, thereby mounting the semiconductorelement 200. In the same manner, combining the plating 35 a which isprovided /grown on the surface of the third wiring 35 shown in FIG. 3and the plating 36 a produced/grown on the surface of the first wiring36, the third wiring 35 and the first wiring 36 are electricallyconnected, electrically connecting the semiconductor element 200 and thepiezoelectric element 300.

In ejecting the functional liquid droplets from the liquid dropletejection head 1 shown in FIG. 3, the un-shown external functional liquidsupply device connected to the functional liquid introduction aperture25 is driven by an external controller (omitted from the drawing)connected to the liquid droplet ejection head 1. The functional liquidsent from the external functional liquid supply device, after beingsupplied to the reservoir 100 through the functional liquid introductionaperture 25, realizes an internal flow circuit of the liquid dropletejection head 1 which reaches the nozzle aperture 15.

Furthermore, the external controller sends a drive power or instructionsignal to the semiconductor element 200 mounted on the reservoir formingsubstrate 20. The semiconductor element 200 receiving the instructionsignal or the like transmits the drive signal to each piezoelectricelement 300 based on the directive from the external controller.

Then, an electric voltage is applied between the respective lowerelectrode film 60 and the upper electrode film 80 corresponding to thepressurizing chamber 12, as a result of which an electric potential isproduced in the flexible film 50, the lower electrode film 60 and thepiezoelectric film 70, and by changing the capacity of each pressurizingchamber 12 by means of displacement, the internal pressure is increased,and liquid droplets are expelled from the nozzle aperture 15.

An explanation of the method of manufacture of the liquid dropletejection head is provided hereafter, with reference to the flowchartdiagram of FIG. 5 and the cross-sectional process diagrams of FIGS. 6Ato 6E.

First of all, an explanation is provided of an outline of theconstruction process of the liquid droplet ejection head, with referenceto FIGS. 5 and 3.

In constructing the liquid droplet ejection head, a laminated layer isformed of the flexible film 50 and lower electrode film 60 on the flowpath forming substrate 10 prior to the etching process shown in FIG. 3.Next, by forming a pattern of the piezoelectric film 70 and the upperelectrode film 80 on the lower electrode film 60, a piezoelectricelement 300 is formed (in step SA1).

Furthermore, in parallel with step SA1, by executing anisotropic etchingon the silicon single crystal substrate, the reservoir forming substrate20 is created (in step SA2) which is provided with the groove 20 a orthe piezoelectric element support 24, the introduction path 26, and areservoir portion 21 and the like. Next, a pattern is formed (in stepSA3) of the third wiring 35 on the side surface, by forming the secondwiring 34 on the surface of the reservoir forming substrate 20.

Next, in a position covering the piezoelectric element 300 on a flowpath forming substrate which has passed step SA1, positional alignmentis accomplished on the reservoir forming substrate 20 which has passedStep SA3, and fixing is accomplished (in step SA4). Subsequently, byexecuting anisotropic etching on the flow path forming substrate formedfrom the silicon single crystal substrate, the pressurizing chamber 12or supply path 14 shown in FIG. 3, and the coupling pare 13 are formed(in step SA5). Next, the semiconductor element 200 on the upper surfaceof the reservoir forming substrate 20 is secured (in step SA6).

Plating is provided in the first through third wiring and the connectionterminal of the semiconductor element, thereby establishing (in stepSA7), a conductive connection between the semiconductor element 200 andthe piezoelectric element 300.

A detailed explanation concerning the manufacturing process of thereservoir forming substrate 20 and the mounting process of thesemiconductor element is provided hereafter, with reference to FIGS. 6Ato 6E, which are diagrams corresponding to the summary cross-sectionalstructure along the line A-A of FIG. 1.

As shown in FIG. 6A, the center of the surface (+Z side surface) of asilicon single crystal substrate 920 is removed by etching, therebyforming the groove 20 a. Specifically, initially the surface of thesilicon single crystal substrate 920 is heat oxidized to form a siliconoxide film. Next, a resist is coated on the surface of the siliconsingle crystal substrate 920, forming the aperture of the resistance onthe part in which the groove 20 a is to be formed by photolithography.The resist aperture is then processed with fluoric acid, forming asilicon oxide film aperture. Still further, the silicon single crystalsubstrate 920 is immersed in an aqueous solution of potassium hydrate(KOH) in a 35 percent weight volume, and anisotropic etching isaccomplished on the silicon single crystal substrate 920 exposed fromthe aperture of the silicon oxide film. Since the silicon oxide filmfunctions as an etching stopper, penetration by the etching of thesilicon single crystal substrate 920 is suspended. After the completionof etching, the surface of the silicon single crystal substrate 920 isagain heat oxidized, forming a silicon oxide film. In the same manner,the reservoir portion 21 and piezoelectric element support 24 are formedby etching.

Next, as shown in FIG. 6B, the second wiring 34 is formed on the uppersurface of the silicon single crystal substrate 920, and the thirdwiring 35 is formed on the side surface 20 b of the groove 20 a.Specifically, first of all coating is accomplished on the surface of thesilicon single crystal substrate 920, by means of a method in which theliquid state of the resin material mixed with a catalyst is spin coatedor spray coated. Next, the resin material is exposed through a mask onwhich has been drawn the pattern of the second wiring 34 and the thirdwiring 35, and developed, thereby patterning the second wiring 34 andthe third wiring 35 on the surface of the silicon single crystalsubstrate 920.

In composing the second wiring 34 and the third wiring 35 with metallicmaterial, a metallic film is formed by means of sputtering, patterningbeing accomplished by means of etching through the resist mask. By asputtering method or inkjet method through the Si mask, the secondwiring 34 may be directly partitioned, thereby forming a reservoirforming substrate 20.

Next, as shown in FIG. 6C, the reservoir forming substrate 20 ispositionally aligned and fixed in a position which covers thepiezoelectric element 300 on the flow path forming substrate 10 prior toetching processing. The first wiring 36 of the piezoelectric element 300extending to the center on the flow path forming substrate 10, in orderto achieve exposure through the groove 20 a formed in the center of thereservoir forming substrate 20, is pre-arranged on both substrates inpatterning. By executing anisotropic etching on the flow path formingsubstrate 10 formed from the silicon single crystal substrate, apressurizing chamber 12 is created. Subsequently, a compliance substrate30 is connected to the reservoir forming substrate 20, and a nozzlesubstrate 16 is connected to the flow path forming substrate 10.

Next, as shown in FIG. 6D, the semiconductor element 200 is attached tothe upper surface of the reservoir forming substrate 20. Specifically,first of all an adhesive 42 formed from a thermoplastic resin materialis coated on the lower surface center of the semiconductor element 200.Next, the connection terminal 44 of the semiconductor element 200 ispositionally aligned with the second wiring 34 of the reservoir formingsubstrate 20, and the semiconductor element 200 is heated and pressureis applied relative to the reservoir forming substrate 20. Here, byadjusting the amount of coating of the adhesive or the amount ofheat/pressure applied when adhering, the gap between the connectionterminal 44 and the second wiring 34 can be set to approximately severalμm-10 μm. Subsequently, the adhesive 42 is hardened by cooling theentire body, and the semiconductor element 200 becomes fixed on theupper surface of the reservoir forming substrate 20. After adhering thesemiconductor element 200 to the reservoir forming substrate 20, thereservoir forming substrate 20 may be fixed to the flow path formingsubstrate 10.

Next, as shown in FIG. 6E, plating 46 is provided on the surface of thefirst wiring 36, the third wiring 35, the second wiring 34 and theconnection terminal 44. Specifically, non-electrolytic plating isexecuted by means of the following process.

First of all, with the objective of improving the wettability of thesurface of each wiring and connection terminal, and the removal ofresidue, submersion is accomplished for 1-5 minutes in an aqueoussolution which includes fluoric acid in an amount of 0.01-0.1 percent,and sulfuric acid in an amount of 0.01-1 percent. Or, immersion may beaccomplished for from 1 to 10 minutes in a 0.1-10 percent aqueoussolution of an alkali base such as sodium hydroxide.

Next, the surface oxide film is removed by immersion for from one secondto 5 minutes in an alkali solution having a pH of 9-13 and which hasbeen heated to 20-60° C., with a sodium hydroxide base. Immersion mayalso be accomplished for from one second to 5 minutes in an acidicaqueous solution having a pH of from 1-3 and which has been heated to20-60° C. using 5-30 percent nitric acid as the base.

Next, immersion is accomplished for from one second to two minutes in azincate liquid solution having a pH of from 11-13 and which hasinclusions of ZnO, and Zn is substituted on the surface of each wiringand connection terminal. Next, immersion is accomplished in a nitricacid solution of from 5-30 percent for from 1-60 seconds, and the Zn isremoved. Once again immersion is accomplished for from one second to twominutes in a zincate solution, and minute particles of Zn are providedon the surface of each wiring and connection terminal.

Next, Ni plating is provided by immersion in a non-electrolytic Niplating solution. Such plating is provided until a high level is reachedof approximately 2-30 μm. Furthermore, the plating solution is asolution in which hypo phosphoric acid is used as the reduction agent,with a pH of 4-5, and a solution temperature of 80-95° C. Phosphorus isprovided owing to the hypo phosphoric acid solution.

Furthermore, the Ni surface may be substituted with Au by immersion in asubstitute Au plating solution. The Au is formed to a thickness ofapproximately 0.05 μm-0.3 μm. Furthermore, as the Au solution, use maybe made of a cyan free type, with a pH of 6-8, and a solutiontemperature of 50-80° C., immersion being accomplished for from 1 to 30minutes.

In this manner, Ni or Ni—Au plating is provided on the surface of eachwiring and connection terminal. Furthermore, execution may beaccomplished of a thickness of Au plating on the Ni—Au wiring. Even ifeach of the wirings including the subterranean plating is thin, theelectrical resistance can be reduced by applying a plating thickness.

Aqueous washing processing is performed between each chemical process.For the washing use is made of an overflow structure, or a QDRmechanism. N₂ bubbling is accomplished from the lowermost surface. Thebubbling method is a method in which N₂ is passed out through openingsin a resin tube or the like or through a sinter combined body. By thismeans, an adequate rinse can be accomplished in a short period of time.

By means of this process, as shown in FIG. 4, plating 44 a is providedon the surface of the semiconductor element 200 and the connectionterminal 44. Until the plating 44 a and the plating 34 a are mutuallycombined, by growing both platings, the connection terminal 44 and thesecond wiring 34 are electrically connected. In the same manner, untilthe plating 35 a provided on the surface of the third wiring 35 and theplating 36 a provided on the surface of the first wiring 36 shown inFIG. 3 are combined, by growing both platings, the third wiring 35 andthe first wiring 36 are electrically connected. By this means, thesemiconductor element 200 and the piezoelectric element 300 areelectrically connected.

By means of the above, the liquid droplet ejection head of the presentembodiment is formed.

As explained above, the liquid droplet ejection head 1 of the presentembodiment is constructed so that the first wiring 36 conductivelyconnected to the piezoelectric element 300 formed on the upper surfaceof the flow path forming substrate 10 and, and the second wiring 34formed on the upper surface of the reservoir forming substrate 20, andthe third wiring 35 formed on the side surface of the reservoir formingsubstrate 20 and the connection terminal 44 of the semiconductor element200 are conductively connected by means of the plating 46 provided onthe surface of each wiring 34-36 and the connection terminal 44.

According to such a construction, as in the case of connecting thesemiconductor element 200 and the first wiring 36 by means of wirebonding, there is no need to provide a wire guide space. Therefore, inaddition to establishing a narrow pitch for the nozzle aperture 15, evenif the first wiring 36 is made to have a narrow pitch, an electricalconnection with the first wiring 36 can be assured, enabling mounting ofthe semiconductor element 200. In other cases as well, in comparisonwith mounting by means of conventional wire bonding, mounting ispossible which has a short TAT, low-cost, and high yield.

Furthermore, even if there is positional slippage or a gap between theconnection terminal 44 and the wiring 36 or mutually between the wiring,an electrical connection can be assured by provided plating.Furthermore, mounting of the semiconductor element 200 and theelectrical connection of each wiring can be simultaneously executed,simplifying the manufacturing process.

Furthermore, since the liquid droplet ejection head 1 is such that thereservoir forming substrate 20 side surface 20 b is an inclined surface,the third wiring 35 can be easily formed. Furthermore, the semiconductorelement 200 and the piezoelectric element 300 can be positivelyelectrically connected.

Furthermore, according to the liquid droplet ejection head 1 of thepresent embodiment, it is possible for the nozzle aperture 15 to begiven a narrow pitch, and if the device is constructed using the appliedliquid droplet ejection head 1, high fine precision and minuteness canbe realized.

Furthermore, according to the mounting structure of the presentembodiment, since a positive electrical connection can be achievedbetween the step difference lower part of the wiring 36 and the stepdifference upper part of the semiconductor element 200, mounting ispossible not only of the liquid droplet ejection head, but also throughstep differences in other devices as well, and broad application can bemade relative to electronic equipment or transport devices or printingdevices and the like.

Second Embodiment

An explanation of the second embodiment of the liquid droplet ejectionhead is provided hereafter, with reference to FIG. 7.

FIG. 7 is an explanatory diagram of the mounting structure according tothe second embodiment, and is an enlarged view of part C of FIG. 8B. Asshown in FIG. 7, in the liquid droplet ejection head according to thesecond embodiment, in addition to the fact that the second wiring 34extends to a position facing the connection terminal 44 of thesemiconductor element 200, there is the point that an electricallyconductive protrusion 45 is protrudingly formed facing the second wiring34, in which regard it differs from the first embodiment. A detailedexplanation concerning construction parts which are the same as in thefirst embodiment is omitted.

In the second embodiment, the second wiring 34 formed on the uppersurface of the reservoir forming substrate 20 extends to a positionfacing the connection terminal 44 of the semiconductor element 200.Furthermore, on the surface of the connection terminal 44 the conductiveprotrusion (bump) 45 is protrudingly formed facing the second wiring 34.The conductive protrusion 45 is formed to a height thickness of fromseveral μm-10 μm by means of a metallic material such as Al or Ni—Cr,Cu, Ni, Au or Ag and the like. The plating 46 is provided so as to coverthe second wiring 34 and protrusion 45.

Next, an explanation is provided of the construction method of theliquid droplet ejection head according to the second embodiment, withreference to the cross-sectional process diagrams in FIGS. 8A and 8B.From the reservoir forming substrate 20 forming process to the fixingprocess of the flow path forming substrate, the process is the same asthe first embodiment, as shown in FIGS. 6A to 6C.

As shown in FIG. 8A, the semiconductor element 200 is pressured to thereservoir forming substrate, and is adhered by the adhesive 42. Owing toaberrations in the height of the protrusion 45, a slight gap may also beformed between the front end of the protrusion 45 and the second wiring34.

Next, as shown in FIG. 8B, the plating 46 is provided on the surface ofeach wiring and the protrusion 45. Specifically, non-electrolyticplating is executed by the same process as that of the first embodiment.In this instance, since the front end of the protrusion 45 is connectedto the second wiring 34, plating can be positively provided on thesurface of both. This would be the same, even if there is a slight gapbetween the front end of the protrusion 45 and the second wiring 34. Bythis means, a positive electrical connection can be established betweenthe connection terminal and the second wiring 34.

As indicated above, in the second embodiment, in addition to the secondwiring 34 extending to a position facing the connection terminal 44 ofthe semiconductor element 200, an conductive protrusion 45 isconstructed so as to be protrudingly formed on the connection terminal44 facing the second wiring 34. Furthermore, in connecting the front endof the protrusion 45 to the second wiring 34, the structure educes theplating 46 on the surface of both.

According to such a structure, it is possible to positively electricallyconnect the semiconductor element 200 connection terminal 44 to thesecond wiring 34, enabling improved reliability of the electricalconnection.

Furthermore, mounting can be accomplished in which the amount of platingwhen electrical connection can be completed is small amount, with shortTAT, at low-cost, and with high yield. Furthermore, in the case ofapplying a plating thickness, since plating is also grown in the lateraldirection of the wiring, making the wiring to have a narrow pitch isdifficult; relative to which, in the second embodiment, since the amountof plating used when electrical connection is small, narrow pitching ofthe wiring and narrow pitching of the nozzle aperture 15 of the liquiddroplet ejection head 1 can be easily accomplished.

In the case of structuring the second wiring 34 with a photosensitiveresin mixed with a catalyst, since the second wiring 34 is flexible,breakage caused by contact with the protrusion 45 can be prevented.Furthermore, in the state in which initial pressure is applied to thesecond wiring 34 by the protrusion 45, it becomes possible for thesemiconductor element 200 to become fixed to the reservoir formingsubstrate 20, with improved reliability of the electrical connection.

Third Embodiment

An explanation is provided concerning the third embodiment of the liquiddroplet ejection head of the present invention, with reference to FIGS.9 to 11. FIG. 9 is a perspective view showing the third Embodiment ofthe liquid droplet ejection head, and FIG. 10 is a partially brokendiagram of the oblique construction diagram in which the liquid dropletejection head is viewed from below, and FIG. 11 is a cross-sectionaldiagram along the line A-A of FIG. 9.

As shown in FIG. 11, the liquid droplet ejection head 1 of the presentembodiment emits functional liquid in liquid droplet form from thenozzle. The liquid droplet ejection head 1 is provided with apressurizing chamber 12 which is coupled to the nozzle aperture 15 fromwhich the liquid droplets are ejected, and the piezoelectric element(driven element) 300 which produces pressure changes in the pressurizingchamber 12 arranged on the upper surface of the pressurizing chamber 12,and the reservoir forming substrate (protected substrate) 20 whichcovers the piezoelectric element 300 is arranged on the upper surface ofthe pressurizing chamber 12, and a semiconductor element 200 whichdrives the piezoelectric element 300 is arranged on the side surface 20b of the reservoir forming substrate 20. Moreover, the operation of theliquid droplet ejection head 1 is controlled by an external controller,not shown in the diagram, and which is connected to the semiconductorelement 200.

As shown in FIG. 10, to the lower side (−Z side) of the liquid dropletejection head 1 is attached the nozzle substrate 16. On the nozzlesubstrate 16 are provided the multiple nozzle apertures 15 which ejectliquid droplets, arranged in the Y axis-direction. In this embodiment,the nozzle apertures 15, of the group arranged in multiple regions onthe nozzle substrate 16, respectively includes a first nozzle aperturegroup 15A, a second nozzle aperture group 15B the third nozzle aperturegroup 15C and the fourth nozzle aperture group 15D.

The first nozzle aperture group 15A and the second nozzle aperture group15B are arranged in a row in the X-axis direction. The third nozzleaperture group 15C is provided on the +Y side of the first nozzleaperture group 15A, and the fourth nozzle aperture group 15D is providedon the +Y side of the second nozzle aperture group 15B. The third nozzleaperture group 15C and the fourth nozzle aperture group 15D are arrangedin a row in the X-axis direction.

In FIG. 10 is shown a construction accomplished by means of 6 nozzleapertures 15 respectively including each of the nozzle aperture groups15A-15D. However, in actuality, each nozzle aperture group is composedof a nozzle aperture 15 including 720 units.

In the upper side (+Z side) of the nozzle substrate 16 is arranged theflow path forming substrate 10. The nozzle substrate 16 and the lowersurface of the flow path forming substrate 10 are fixed, for example,through an adhesive or thermal deposition material, or a film or thelike. The flow path forming substrate 10 can be structured with silicon,glass or a ceramic material or the like, and in the present embodimentis formed by silicon. The inside of the flow path forming substrate 10has multiple partition walls 11 which extend in the X direction from thecenter. The partition walls 11 are formed such that the silicon singlecrystal substrate including the welded base metal of the flow pathforming substrate 10 is partially removed by anisotropic etching. Bymeans of the partition walls 11, in the flow path forming substrate 10,aperture regions have a comb-shape. From among these aperture regions,parts formed extending in the X-axis direction compose the pressurizingchamber 12 encompassed by the nozzle substrate 16 and an oscillationplate 400. The pressurizing chamber 12 houses the functional liquid,which is ejected from the nozzle aperture 15 by means of pressureapplied when operating the liquid droplet ejection head 1.

Each pressurizing chamber 12 is provided corresponding to the multiplenozzle apertures 15. In other words, the pressurizing chamber 12 isprovided with multiple rows in the Y-axis direction so as to correspondto the multiple nozzle apertures 15 which respectively compose thefirst-fourth nozzle aperture groups 15A-15D. The multiply formedpressurizing chambers 12 corresponding to the first nozzle aperturegroup 15A compose the first pressurizing chamber group 12A, and themultiply formed pressurizing chambers 12 corresponding to the secondnozzle aperture group 15B compose the second pressurizing chamber group12B. The multiply formed pressurizing chambers 12 corresponding to thethird nozzle aperture group 15C compose the third pressurizing chambergroup 12C. The multiply formed pressurizing chambers 12 corresponding tothe fourth nozzle aperture group 15D compose the fourth pressurizingchamber group 12D. The first pressurizing chamber group 12A and thesecond pressurizing chamber group 12B are arranged in a row in theX-axis direction. Between these are formed partition walls 10K extendingin the Y-axis direction. In the same manner, the third pressurizingchamber group 12C and the fourth pressurizing chamber group 12D arearranged in a row in the X-axis direction, between which are the formedpartition walls 10K extending in the Y-axis direction.

Furthermore, among the aperture regions having a comb-shape formed inthe flow path forming substrate 10, the part formed to extend in the Ydirection shown in the drawing composes the reservoir 100. The end ofthe substrate outside border side (+X side) in the multiple pressurizingchambers 12 forming the first pressurizing chamber group 12A isconnected to the reservoir 100. The reservoir 100 supports in reservethe functional liquid supplied to the pressurizing chamber 12 becomingthe joint functional liquid maintenance chamber (ink chamber) of themultiple pressurizing chambers 12 composing the first pressurizingchamber group 12A. To the respective second, third, and fourthpressurizing chamber groups 12B, 12C, and 12D is also connected thereservoir 100, in the same manner, and composes temporary storage forthe functional liquid supplied to the respective pressurizing chambergroups 12B-12D.

As shown in FIG. 11, the reservoir 100 is composed from the reservoirportion 21 formed in the reservoir forming substrate 20, and a coupler13 formed in the flow path forming substrate 10. The coupler 13 has thefunction of connecting the reservoir portion 21 to each of therespective pressurizing chambers 12. To the outside (the side of theflow path forming substrate 10) of the reservoir forming substrate 20 isconnected the compliance substrate 30 which has a constructionlaminating the sealing film 31 and the fixed plate 32. In the compliancesubstrate 30, the internally arranged sealing film 31 is formed from amaterial having low elasticity (for example a polyphenylene sulfide filmof a thickness of approximately 6 μm). On the other hand, the fixedplate 32 arranged on the outside is formed from a hard metallic material(for example stainless steel having a thickness of approximately 30 μm).In the fixed plate is formed an aperture 33 formed from a cut out of theplane surface region corresponding to the reservoir 100. By this means,the upper part of the reservoir 100 is sealed by only the elasticsealing film 31, and becomes an elastic unit 22, deformable throughchanges in internal pressure. Furthermore, in the compliance substrate30 is formed the functional liquid introduction aperture 25 throughwhich to functional liquid is supplied to the reservoir 100. Thereservoir forming substrate 20 is provided with an introductory path 26which couples the functional liquid introductory path 25 and thereservoir 100.

The functional liquid introduced from the functional liquid introductionpath 25 flows into the reservoir 100 through the introductory path 26,and is supplied to the respective multiple pressurizing chambers 12composing the first pressurizing chamber group 12A through the supplypath 14. Through heat on the periphery, or the flow of the functionalliquid when driving the piezoelectric element 300, there is a concernthat pressure changes will occur within the reservoir 100. However,since the elastic part 22 of the reservoir 100 is deflected anddeformed, since the pressure changes are absorbed, the inside of thereservoir 100 is ordinarily maintained at a fixed pressure.

On the surface side (+Z side) of the flow path forming substrate 10 isarranged an oscillation plate 400. The oscillation plate 400 has aconstruction which successively laminates the flexible film 50 and thelower electrode film 60 from the flow path forming substrate 10. Theflexible film 50 arranged on the flow path forming substrate 10 side isformed from a silicon oxide film have a thickness, for example, of 1-2μm, and the lower electrode film 60 is formed from metallic film havinga thickness of, for example, 0.2 μm. In the present embodiment, thelower electrode film 60 functions as a joint electrode with multiplepiezoelectric elements 300 arranged between the flow path formingsubstrate 10 and the reservoir forming substrate 20.

On the upper surface side (+Z side) of the oscillation plate 400 isarranged the piezoelectric element 300 for deforming the oscillationplate 400. The piezoelectric element 300 has a construction whichlaminates, chronologically from the lower electrode film 60 side, thepiezoelectric body film 70 and the upper electrode film 80. Thepiezoelectric body film 70 is formed, for example, from a PZT filmhaving a thickness of approximately 1 μm. The upper electrode film 80 isformed, for example, from a metallic film having a thickness ofapproximately 0.1 μm.

The piezoelectric element 300, in addition to the piezoelectric bodyfilm 70 and the upper electrode film 80, may also include the lowerelectrode film 60. Whereas, the lower electrode film 60 functions as thepiezoelectric element 300, it may also function as the oscillation plate400. With the present embodiment, a structure is adopted in which theflexible film 50 and the lower electrode film 60 function as theoscillation plate 400. However, by eliminating the flexible film 50, thelower electrode film 60 may also be made to function jointly as theflexible film 50.

The piezoelectric elements 300 (piezoelectric body film 70 and the upperelectrode film 80) are multiply provided corresponding to multiplenozzle apertures 15 and pressurizing chambers 12. In the presentembodiment, conveniently, the first piezoelectric element 300 groupprovided in multiple rows in the Y axis direction so as to effectivelycorrespond to the nozzle apertures 15 composing the first nozzleaperture group 15A is called the first piezoelectric element group, andthe first piezoelectric element 300 provided in multiple rows in theY-direction respectively corresponding to the nozzle apertures 15composing the second nozzle aperture group 15B is called the secondpiezoelectric element group. Furthermore, the piezoelectric elementgroup corresponding to the third nozzle aperture group is called thethird piezoelectric element group, and the first piezoelectric elementgroup corresponding to the fourth nozzle aperture is called the fourthpiezoelectric element group, the first piezoelectric element group andthe second piezoelectric element group being arranged in a row in theX-axis direction, and the third piezoelectric element group and thefourth piezoelectric element being arranged in rows in the X-axisdirection.

The reservoir forming substrate (protective substrate) 20 is arranged onthe upper surface side (+Z side) of the flow path forming substrate 10so as to cover the piezoelectric element 300. Since the reservoirforming substrate 20, along with the flow path forming substrate 10, isa member that forms a part of the liquid droplet ejection head 1, as astructural member, it is desirable for use to be made of a rigidmaterial that has roughly the same thermal expansion ratio as the flowpath forming substrate 10. In the case of the present embodiment, sincethe flow path forming substrate 10 is formed from silicon, optimal useshould be made of a silicon single crystal substrate of the samematerial. Since the silicon substrate can easily execute precisionprocessing by means of anisotropic etching, the piezoelectric elementsupport 24 described hereafter has the advantage of being easily formed.In the same manner as with the flow path forming substrate 10, it mayalso be composed of a reservoir forming substrate 20 which uses glass orceramic material or the like.

The reservoir forming substrate 20 is provided with the seal 23 whichtightly seals the piezoelectric element 300. In the case of the presentembodiment, the part which seals the first piezoelectric element groupis called the first seal 23A, and the part which seals the secondpiezoelectric element group is called the second seal 23B. In the samemanner, the part which seals the third piezoelectric element group iscalled the third seal, and the part which seals the fourth piezoelectricelement group is called the fourth seal. The seal 23 is provided with apiezoelectric element support (element support) 24 formed from theindentation of the plane surface visually abbreviated rectangular shapeextending in the direction vertical from the paper surface of FIG. 11.The piezoelectric element support 24, in addition to assuring space sothat movement of the piezoelectric element 300 in the periphery of thepiezoelectric element 300 is not obstructed, has the function of tightlysealing the space. The piezoelectric element 70 support 24 hasmeasurements which enable sealing of at least the piezoelectric filmfrom among the piezoelectric elements 300. Furthermore, thepiezoelectric element support 24 may also be partitioned for each ofmultiple piezoelectric elements 300.

In this manner, the reservoir forming substrate 20 functions as aprotective substrate which shields the piezoelectric element 300 fromthe outside environment. By sealing the piezoelectric element 300 bymeans of the reservoir forming substrate 20, characteristicdeterioration and the like of the piezoelectric element 300 caused byexternal aqueous components and the like can be prevented. Furthermore,in the current embodiment, the inside of the piezoelectric elementsupport 24 is made to only be in a sealed state. However, by creating avacuum, or an environment of nitrogen or argon or the like, the insideof the piezoelectric element support 24 can be maintained at lowhumidity, by which structural deterioration of the piezoelectric element300 can be effectively prevented.

In the reservoir forming substrate 20, the groove 20 a is providedbetween the first seal 23A and the second seal 23B, which penetrates thereservoir forming substrate 20. Through the groove 20 a, the uppersurface of the flow path forming substrate is exposed to the outside.Making the upper surface of the exposed flow path forming substrate tobe a lower step surface, the upper surface of the seal 23 of thereservoir forming substrate 20 can be made to be an upper step surface,thereby composing a stepped body.

The side surface 20 b of the groove 20 a of the reservoir formingsubstrate 20 which combines the upper surface of the seal 23 of thereservoir substrate 20 and the upper surface of the flow path formingsubstrate 10 is an inclined surface. In particular, the reservoirforming substrate 20 is composed of a silicon substrate having a <1, 0,0> orientation, and if the silicon substrate is subjected to wet etchingwith an alkali solution of KOH and the like, then an inclined surface ofapproximately 54° can be made of the side surface 20 b of the groove 20a through differences in the etching rate in each surface direction.

Among the piezoelectric elements 300 sealed by the piezoelectric elementsupport 24 of the reservoir forming substrate 20, the end of the-X sideof the upper electrode film 80 is extended to the upper surface of theexposed flow path forming substrate 10, thereby composing the firstwiring 36. The first wiring 36 is composed of a metallic material of Alor Ni—Cr, Cu, Ni, Au, and Ag and the like. However, it is also possiblefor it to be composed of a photosensitive resin material mixed with acatalyst, as with the second wiring 34 described hereafter. When thelower electrode film 60 is arranged in an abbreviated beta state on theflow path forming substrate 10, the insulation film 600 for preventingshort-circuiting between the two is arranged between the upper electrodefilm 80 which extends to the outside of the piezoelectric elementssupport 24 and the lower electrode film 60. Furthermore, the upperelectrode film 80, in lieu of being extended in its existent state mayalso form electrode wiring electrically connected to the upper electrode80 on the flow path forming substrate 10, with the electrode wiringbeing drawn to the outside of the piezoelectric elements support 24, asthe first wiring 36.

On the upper surface of the reservoir forming substrate 20, a secondwiring 34 is formed in order to electrically connect the semiconductorelement, described hereafter, to the external controller. The secondwiring 34 is desirably constructed with a resin material mixed with acatalyst. Specifically, it is composed of a photosensitive resinmaterial in which minute particles of Pd (Palladium) are dispersed. Inthis case, it is possible to form the second wiring 34 by means ofphotolithography. In other words, the resin material is coated on theupper surface and the side surface of the reservoir forming substrate20, and patterning of the second wiring 34 is accomplished by means ofexposure and development.

The second wiring 34 may also be the composed of a metallic material ofAl, or Ni—Cr, Cu, Ni, Au, and Ag and the like. However, in patterningthe metallic material it is necessary for the resist to be etched as amask, complicating the manufacturing process. In this regard, if it iscomposed of a photosensitive resin substance mixed with a catalyst, itis possible for the second wiring 34 to be patterned by only means ofphotolithography, simplifying the manufacturing process.

On the side surface 20 b of the groove 20 a formed on the reservoirforming substrate 20, the semiconductor element 200 is arranged in aface down state. The semiconductor element 200 is constructed toinclude, for example, a circuit substrate or a semiconductor circuit(IC) which includes a drive circuit. The width of the semiconductorelement 200 is formed to be equivalent to the height of the side surface20 b of the reservoir forming substrate 20. As shown in FIG. 9, in thepresent embodiment, four semiconductor elements 200A-200D are arrangedto drive the first-fourth piezoelectric element groups.

In the center of the lower surface side (−Z side) of the semiconductorelement 200 shown in FIG. 11 b is arranged the adhesive 42 formed from athermal elastic material composed of polyimide and the like. By heatingthe semiconductor element 200, and adding pressure to the reservoirforming substrate 20, the semiconductor element 200 will adhere to theside surface 20 b of the reservoir forming substrate 20.

Furthermore, in the peripheral border of the lower surface side (−Zside) of the semiconductor element 200 are provided multiple connectionelements 44. Each connection element 44 is composed of a metallicmaterial of Al or Ni—Cr, Cu, Ni, Au, and Ag and the like. On theperiphery of the-X side of the semiconductor element 200 A, the samenumber of connection elements 44 as in the first wiring 36 are arrangedin a row with the same pitch as the first wiring 36, for use inaccomplishing an electrical connection with a piezoelectric element 300.Furthermore, on the peripheral margin of the X side of the semiconductorelement 200A the same number of connection elements 44 as in the secondwiring 34 are arranged in a row at the same pitch as that of the secondwiring 34, for use in accomplishing an electrical connection with anexternal controller. By adjusting the amount of the adhesive arranged onthe bottom surface of the semiconductor element 200 and the amount ofheat and pressure applied during adhesion, gaps are respectively formedof approximately several μm-10 μm between a connection terminal 44 s andthe first wiring 36, and between a connection element 44 r and thesecond wiring 34.

In this manner, since there is a gap between the connection terminal 44s in the first wiring 36, in this state, there is no electricalconnection between the semiconductor element 200 and the piezoelectricelement 300. Therefore, the plating 46 is provided on the surface ofeach wiring and connection element. Specifically, the plating 36 isprovided on the surface of the first wiring 36, a plating 34 a isprovided on the surface of the second wiring 34, and a plating 44 a isprovided on the surface of the connection terminals 44 r, and 44 srespectively. With the second wiring 34 composed of resin material mixedwith a catalyst, the plating 34 a is provided relative to the catalyst.These plating 46 are composed of a metallic material composed of Cu orNi and Au and the like. The plating 46 may also be provided of differentmaterials on the surface of each wiring and connection element.

FIG. 12 is explanatory diagram of the mounting structure according tothe present embodiment, and is an enlarged diagram of part B of FIG.14E. As shown in FIG. 12, the plating 44 a is provided on the surface ofthe connection element 44 r of semiconductor element 200. The plating 34a is provided on the surface of the second wiring 34. The connectionterminal 44 and the second wiring 34 are electrically connected bycombining the grown plating 44 a and 34 a. In the same manner, theprovided grown plating 44 a on the surface of the connection terminal 44s of the semiconductor element 200 shown in FIG. 11 and the providedgrown plating 36 a on the surface of the first wiring 36 are combined,thereby electrically connecting the connection terminal 44 s and thefirst wiring 36, by which the semiconductor element 200 is mounted, andthe semiconductor element 200 and the piezoelectric element 300 areelectrically connected.

By means of the liquid droplet ejection head 1 shown in FIG. 11, inejecting the liquid droplets of the functional liquid, an un-shownexternal functional liquid supply device is driven, which is connectedto the functional liquid introduction aperture 25 by means of anexternal controller (omitted from the drawing) connected to the liquiddroplet ejection head 1. After supplying the functional liquid sent fromthe external functional liquid supply device to the reservoir 100through the functional liquid introduction aperture 25, an internal flowpath is achieved for the liquid droplet ejection head 1 which reachesthe nozzle aperture 15.

Furthermore, the external controller sends driving power or aninstruction signal to the semiconductor element 200 mounted on thereservoir forming substrate 20. The semiconductor element 200 whichreceives the instruction signal sends a drive signal to eachpiezoelectric element 300 based on the instructions from the externalcontroller.

As a result of applying an electric voltage between the lower electrodefilmed 60 and the upper electrode filmed 80 respectively correspondingto the pressurizing chamber 12, displacement is produced in the flexiblefilm 50, the lower electrode film 60 and the piezoelectric body film 70,changing the capacity of each pressurizing chamber 12, increasing theinternal pressure, and ejecting liquid droplets from the nozzle aperture15.

An explanation is provided of the method of manufacture of the liquiddroplet ejection head hereafter, with reference to the flowchart diagramof FIG. 13 and the cross-sectional process diagrams 14A-14E.

First of all, an explanation is provided of an outline of themanufacturing process of the liquid droplet ejection head, withreference to FIG. 13 and FIG. 11.

In constructing the liquid droplet ejection head, a laminate is formedon the flow path forming substrate 10 composed of the flexible film 50and the lower electrode film 60 prior to the etching process, shown inFIG. 11, and then, by the accomplishment of pattern formation of thepiezoelectric body film 70 and the electrode film 80 on the lowerelectrode film 60, formation can be accomplished of the piezoelectricelement 300 (in step SA1).

Furthermore, in parallel to step SA1, by executing anisotropic etchingon the silicon single crystal substrate, a reservoir forming substrate20 is created (in step SA2) which is provided with the groove 20 a, thepiezoelectric element support 24, the introduction path 26, and thereservoir portion 21 and the like. Next, the second wiring 34 is formedon the upper surface of the reservoir forming substrate 20.

Next in a position which covers the piezoelectric element 300 on theflow path forming substrate and which has passed step SA1, the reservoirforming substrate 20 which has passed step SA3 is positionally alignedand fixed (in step SA4). Subsequently, by executing anisotropic etchingon the flow path forming substrate 10 formed from the silicon singlecrystal substrate, the pressurizing chamber 12, the supply path 14, andthe coupler 13 and the like shown in FIG. 11 can be created (in stepSA5). Subsequently, a semiconductor element 200 can be attached (in stepSA6) to the side surface 20 b of the groove 20 a of the reservoirforming substrate 20. Next, plating is provided on the connectionterminal 300 of the first and second wiring, and semiconductor element200.

By means of the above process, a liquid droplet ejection head 1 can beconstructed on which is mounted a semiconductor element 200.

Next, a detailed description is provided concerning the manufacturingprocess of the reservoir forming substrate 20 and the mounting processof the semiconductor element, with reference to FIGS. 14A to 14E. FIGS.14A to 14E are diagrams which correspond to the abbreviatedcross-sectional structure taken along the line A-A of FIG. 9.

As shown in FIG. 14A, the center of the upper surface (+Z side surface)of the silicon single crystal substrate 920 is removed by etching,forming the groove 20 a. Specifically, first of all the silicon oxidefilm is formed by the thermal oxidation of the surface of the siliconsingle crystal substrate 920. Next, the resist on the surface of thesilicon single crystal substrate 920 is coated, forming the aperture ofa resist in the part of the groove 20 a which should be formed. Next,the aperture of the resist is processed with fluoric acid, forming asilicon oxide film aperture on the part which should form the groove 20a. Then, the silicon single crystal substrate 920 is immersed in asolution of potassium hydroxide (KOH) having a percentage weight of 35percent, and anisotropic etching is performed of the silicon singlecrystal substrate 920 exposed from the aperture of the silicon oxidefilm. Since the silicon oxide film functions as an etching stopper, theetching suspends the penetration of the silicon single crystal substrate920. After the completion of etching, a silicon oxide film is formed bythe reheated oxidation of the surface of the silicon single crystalsubstrate 920. In the same manner, the reservoir portion 21 andpiezoelectric element support 24 are formed by etching.

Next, as shown in FIG. 14B, the second wiring 34 is formed on the uppersurface of the silicon single crystal substrate 920. Specifically, firstof all, the liquid state of the resin material mixed with a catalyst iscoated by means of the spin coating method on the surface of the siliconsingle crystal substrate 920. Next, the resin material is exposed anddeveloped through a mask in which the second wiring 34 is partitioned,patterning the second wiring 34 on the surface of the silicon singlecrystal substrate 920.

In the case of structuring the second wiring 34 with a metallicmaterial, a metallic film formed by sputtering, and patterning isaccomplished by means of etching through a resistant mask.

By means of a sputtering method accomplished through an Si mask, or thejet method, direct connect partitioning may be accomplished of thesecond wiring 34, thereby forming the reservoir forming substrate 20.

Next, as shown in FIG. 14C, in a position which covers the piezoelectricelement 300 on the flow path for a substrate and prior to etchingprocessing, the reservoir forming substrate 20 is positionally alignedand fixed. The first wiring 36 of the piezoelectric element 300extending to the center on the flow path forming substrate 10, in orderto accomplish exposure through the groove 20 a within the center of thereservoir forming substrate 20, in pre-patterning the first wiring 36,arranges both substrates. Next, the pressurizing chamber 12 and the likeis created by executing anisotropic etching on the flow path formingsubstrate 10 formed from the silicon single crystal substrate.Subsequently, the compliance substrate 30 is connected to the reservoirforming substrate 20, connecting the nozzle substrate 16 to the flowpath forming substrate 10.

Next, as shown in FIG. 14D, the semiconductor element 200 is connectedto the upper surface of the reservoir forming substrate 20.Specifically, first of all, the lower surface center of thesemiconductor element 200 is coated with an adhesive 42 formed from athermal elastic resin material. Next, the connection terminal 44 s ofthe semiconductor element 200 is positionally aligned with the firstwiring 36, and the connection terminal 44 r is positionally aligned withthe second wiring 34. The semiconductor element 200 is heated, andpressure is applied relative to the reservoir forming substrate 20. Byadjusting the amount of coating or the amount of heat/pressure of theadhesive, the gap between the connection terminal 44 s and the firstwiring 36 and the gap between the connection terminal 44 r and thesecond wiring 34 are respectively set to from several μm-10 μm.Subsequently, the entire body is cooled, and the adhesive 42 ishardened, adhering the semiconductor element 200 to the upper surface ofthe reservoir substrate 20. After adhering the semiconductor element 200to the reservoir forming substrate 20, the reservoir forming substrate20 may also be fixed to the flow path forming substrate 10.

Next, as shown in FIG. 14E, the plating 46 is provided on the surface ofthe first wiring 36, the second wiring 34, and the connection terminals44 r and 44 s. Specifically, non-electrolytic plating is executed bymeans of the following processes.

With the objective of improving wettability of the surface of eachwiring and connection terminal, and removing the residue, immersion isaccomplished for from one to five minutes in a solution of 0.01-0.1percent fluoric acid, and 0.01-1 percent sulfuric acid. Or, immersionmay also be accomplished for from 1 to 10 minutes in an aqueous solutionof an alkali base including 0.1-10 percent sodium hydroxide.

Next, the surface oxide film is removed by immersion for from one secondto five minutes in an alkali aqueous solution heated to 20-60° C. with apH of 9-13 with a sodium hydroxide base. Immersion may also beaccomplished for from one second to five minutes in an acid solutionheated to 20-60° C., and having a pH of 1-3 in which 5-30 percent nitricacid serves as the base.

Next, substituting Zn on the surface of each wiring and connectionterminal is accomplished by immersion for from one second to two minutesin a zincate solution having a pH of 11-13, and inclusions of ZnO. Next,the Zn is peeled off through immersion for from one to 60 seconds in a5-30 percent nitric acid solution. Tight Zn particles can be provided onthe surface of each wiring and connection terminal by re-immersion forfrom one to two seconds in the zincate solution.

Next, Ni plating is provided by immersion in a non-electrolytic Niplating solution. This plating is provided to a height of from 2-30 μm.Furthermore, the plating solution is a solution in which hypo phosphoricacid is the reducing agent, with a pH of 4-5 and a solution temperatureof 80-95° C. Phosphorus is co-produced owing to the hypo phosphoric acidsolution.

Furthermore, the Ni surface may also be substituted by Au, by immersionin the substitute Au plating solution. The Au is formed to a thicknessof approximately 0.05 μm-0.3 μm. Furthermore, the Au solution makes useof a cyan free type, with a pH of 6-8, and a solution temperature of50-80° C., with immersion taking place for 1-30 minutes.

In this manner, Ni or Ni—Au plating is provided on the surface of eachwiring and connection terminal. Furthermore, Au plating may be executedto a thickness on the Ni—Au wiring. Even if each of the wiring includingthe subterranean plating is thin, the electrical resistance can bereduced by the application of a plating thickness.

Aqueous washing processing is accomplished between each chemicalprocess. As the washing vat, use may be made of an overflow structure ora QDR mechanism, with N₂ bubbling occurring from the bottommost surface.The bubbling method is a method of expelling N₂ through openings in aresin tube or the like, or a method of expelling N₂ through a sinteredbody, by which rinsing can be accomplished with adequate effect over ashort period of time.

By means of this process, as shown in FIG. 12, plating 44 a is providedon the surface of the connection terminal 44 r of the semiconductorelement 200, and plating 34 a is provided on the surface of the secondwiring 34. By growing both platings until the plating 44 a and plating34 a mutually combine, an electrical connection is accomplished betweenthe connection terminal 44 r and the second wiring 34. In the samemanner, by growing both platings until the plating 44 a is provided onthe surface of the connection terminal 44 s shown in FIG. 11, and theplating 36 a is provided on the surface of the first wiring 36 combine,the connection terminal 44 s and the first wiring 36 are electricallyconnected, thereby mounting the semiconductor element 200, and thesemiconductor element 200 and the piezoelectric element 300 areelectrically connected, forming the liquid droplet ejection head of thepresent embodiment.

As indicated above, with the liquid droplet ejection head 1 of thepresent embodiment, the first wiring 36 is electrically connected to thepiezoelectric element 300 formed on the upper surface of the flow pathforming substrate 10, the second wiring 34 formed on the upper surfaceof the reservoir forming substrate 20, and the connection terminal 44 ofthe semiconductor element arranged on the side surface 20 b of thereservoir forming substrate 20 is electrically connected by platingprovided on the surface of each wiring 34 and 36, and the connectionterminal 44.

According to such a structure, since the semiconductor element 200 canbe electrically connected relative to the first wiring 36 of thepressurizing chamber 12 and the second wiring 34 of the reservoirforming substrate 20, there is no need to provide a wire guide for wirebonding. Owing to this, even if the first wiring 36 is of a narrowpitch, in accompaniment with making a narrow pitch on the nozzleaperture 15, the semiconductor element 200 can be mounted, whileassuring an electrical connection with the first wiring 36. Otherwise,in comparison with mounting accomplished by conventional wire bonding,mounting is possible with a short TAT, at low-cost, and with high yield.

Furthermore, even if there is positional slippage between the connectionterminal 44 of the semiconductor element 200 and the wiring 34 and 36,caused by manufacturing errors and the like, an electrical connectioncan be assured by the provided plating 46. Furthermore, since there isno wiring formed on the side surface 20 b of the reservoir substrate 20,there is no need to use a special coating device such as a spray coateror special light exposure technology or the like. Since all of thewiring connections can be completed by mounting the semiconductorelement 200, the manufacturing process is simplified.

Furthermore, since with the liquid droplet ejection head 1 of thepresent embodiment, the side surface 20 b of the reservoir formingsubstrate 20 is an inclined surface, in comparison with when the sidesurface 20 b is a vertical surface, increasing the pressure of thesemiconductor element 200 relative to the side surface 20 b can beeasily executed, and the semiconductor element 200 can be easilymounted.

According to the liquid droplet ejection head 1 of the presentembodiment, a nozzle aperture 15 can be made to have a narrow pitch, andif a device is constructed which uses the subject liquid dropletejection head 1, then a device having high precision and minute finenesscan be realized.

Furthermore, according to the mounting structure of the presentembodiment, since the wiring 36 of the lower step surface of a steppedbody and wiring 34 of the upper step surface and the semiconductorelement 200 can be positively electrically connected, not only with theliquid droplet ejection head, but also with other devices as well,mounting becomes possible of a semiconductor element onto a steppedbody, and can be broadly applied relative to electronic equipment ortransport equipment, or printing equipment or the like.

Fourth Embodiment

An explanation of the fourth embodiment of the liquid droplet ejectionhead according to the present invention is provided hereafter, withreference to FIG. 15 to FIG. 17. FIG. 15 is a perspective view of aliquid droplet ejection head according to the fourth embodiment, FIG. 16is a partially broken diagram of an oblique structure viewing the liquiddroplet ejection head from the bottom side, and FIG. 17 is across-sectional structural diagram along line A-A of FIG. 15.

As shown in FIG. 17, the liquid droplet ejection head 1 of the presentembodiment forms functional liquid into droplets, and ejects it from anozzle. The liquid droplet ejection head 1 is provided with thepressurizing chamber (first member) 12 coupled to the nozzle aperture 15from which the liquid droplets are ejected, and the piezoelectricelement (driven element) 300 which produces pressure changes on thepressurizing chamber 12 arranged on the upper surface of thepressurizing chamber 12, and the reservoir forming substrate (protectivesubstrate, second member) 20 covering the piezoelectric element 300 isarranged on the upper surface of the pressurizing chamber 12, and thesemiconductor element 200 which drives the piezoelectric element 300arranged on the upper surface of the reservoir forming substrate 20.Furthermore, the operation of the liquid droplet ejection head 1 iscontrolled by an un-shown external controller connected to thesemiconductor element 200.

As shown in FIG. 16, to the lower side (−Z side) of the liquid dropletejection head FIG. 1 is mounted the nozzle substrate 16. On the nozzlesubstrate 16 is provided multiple nozzle apertures 15, arranged in theY-axis direction. In the present embodiment, a group of nozzle apertures15 arranged in multiple regions on the nozzle substrate 16 isrespectively referred to as the first nozzle aperture group 15A, thesecond nozzle aperture group 15B, the third nozzle aperture group 15Cand the fourth nozzle aperture group 15D.

The first nozzle aperture group 15A and the second nozzle aperture group15B are arranged in a row in the X-axis direction. The third nozzleaperture group 15C is provided on the +Y-side of the first nozzleaperture group 15A, and the fourth nozzle aperture group 15D is providedon the +Y side of the second nozzle aperture group 15B. The third nozzleaperture group 15C and the fourth nozzle aperture group 15D are arrangedin a row in the X-axis direction.

In FIG. 16, each of the respective nozzle aperture groups 15A-15D isshown as constructed by the six nozzle apertures 15, however, inactuality each of the nozzle aperture groups, for example, is composedby 720 units of the nozzle apertures 15.

On the upper side (+Z side) of the nozzle substrate 16 is arranged theflow path forming substrate 10. The lower surface of the flow pathforming substrate 10 and the nozzle substrate 16, for example, are fixedby an adhesive or a thermal adhesive film or the like. The flow pathforming substrate 10 may be structured with a silicon, glass, or ceramicmaterial and the like, and in the case of the present embodiment isformed of silicon. On the inside of the flow path forming substrate 10is formed multiple partition walls 11 which extend in the X directionfrom the center. The partition walls 11 are formed by partially removingthe silicon single crystal substrate including the welded base of theflow path forming substrate 10 by means of anisotropic etching. By meansof the partition wall 11, in the flow path forming substrate 10 arepartitions formed by multiple flat visibly abbreviated comb-shapeaperture regions. Among these aperture regions, parts formed extendingin the X-axis direction compose the pressurizing chamber (first member)12 encompassed by the nozzle substrate 16 and the oscillation plate 400.The pressurizing chamber 12 houses the functional liquid, and ejectsfunctional liquid from the nozzle aperture 15 by pressure applied whenoperating the liquid droplet ejection head 1.

Each of the pressurizing chambers 12 is provided corresponding to themultiple nozzle apertures 15. In other words, the pressurizing chamber12 is provided in multiple rows in the Y-axis direction, so as tocorrespond to the multiple nozzle apertures 15 respectively composingthe first-fourth nozzle aperture groups 15A-15D. The pressurizingchamber 12 multiply formed corresponding to the first nozzle aperturegroup 15A composes the first pressurizing chamber group 12A. Themultiply formed pressurizing chamber 12 corresponding to the secondnozzle aperture group 15B composes the second pressurizing chamber group12B, the pressurizing chamber 12 multiply formed corresponding to thethird nozzle aperture group 15C composes the third pressurizing chambergroup 12C, and the pressurizing chamber 12 multiply formed correspondingto the fourth nozzle aperture group 15D composes the fourth pressurizingchamber group 12D. The first pressurizing chamber group 12A and thesecond pressurizing chamber group 12B are arranged a row in the X-axisdirection, and between them is formed the partition wall 10K extendingin the Y-axis direction. In the same manner, the third pressurizingchamber group 12C and the fourth pressurizing chamber group 12D arearranged in a row in the X-axis direction, and the partition wall 10Kextending in the Y-axis direction is also formed between them.

Furthermore, among the aperture regions having the comb-shape formed onthe flow path forming substrate 10, the part formed extending in the Ydirection shown in the diagram composes the reservoir 100. The end ofthe substrate outside the border side (+X side) in the multiplepressurizing chambers 12 forming the first pressurizing chamber group12A is connected to the reservoir 100 referred to above. The reservoir100 maintains in reserve the functional liquid supplied to thepressurizing chamber 12, becoming the common functional liquidmaintenance chamber (ink chamber) of multiple pressurizing chambers 12composing the first pressurizing chamber group 12A.

To the respective second, third, and fourth pressurizing chamber groups12B, 12C and 12D as well, are connected reservoirs 100, in the samemanner as described above, which function as temporary storage for thefunctional liquid supplied to the respective pressurizing chamber groups12B-12D.

As shown in FIG. 17, the reservoir 100 is composed from a reservoirportion 21 formed in the reservoir forming substrate 20 and the coupler13 formed in the flow path forming substrate 10. The coupler 13 has thefunction of connecting the reservoir portion 21 to each of therespective pressurizing chambers 12. To the outside (the opposite sideof the path-forming substrate 10) of the reservoir forming substrate 20,is connected the compliance substrate 30 having construction whichlaminates the seal film 31 and the fixed film 32.in the compliancesubstrate 30, and the sealing film 31 arranged on the inside is formedof a material having low elasticity (for example, from polyphenylenesulfide film, having a thickness of 6 μm).

On the other hand, the fixed plate 32 arranged on the outside is formedfrom a material having a metallic hardness and the like (for example,stainless steel having a thickness of 30 μm). On the fixed plate 32, isformed the aperture 33 cut out of a flat region corresponding to thereservoir 100. By such a structure, the upper part of the reservoir 100is sealed only with the elastic sealing film 31, and becomes the elasticcomponent 22 which is capable of deformation by changes in the internalpressure. Furthermore, in the compliance substrate 30 is formed thefunctional liquid introduction aperture 25 for supplying functionalliquid to the reservoir 100. The reservoir forming substrate 20 isprovided with the introduction path 26 which communicates with thefunctional liquid introduction aperture 25 and the reservoir 100.

The functional liquid introduced from the functional liquid introductionaperture 25 flows into the reservoir 100 through the introduction path26, and having further passed the supply path 14, is respectivelysupplied to the multiple pressurizing chambers 12 composing the firstpressurizing chamber group 12A.

By means of the flow of the functional liquid or the peripheral heatwhen driving the piezoelectric element 300, pressure changes areproduced in the reservoir 100. However, since the elastic unit of thereservoir 100 is elastically deformed, and absorbs the pressure changes,the inside of the reservoir 100 normally maintains a fixed pressure.

On the upper surface side (+Z side in FIG. 17) of the flow path formingsubstrate is arranged the oscillation plate 400. The oscillation plate400 is composed so as to laminate, chronologically from the flow pathforming substrate 10 side, the flexible film 50, and the lower electrodefilm 60.

The flexible film 50 arranged on the flow path forming substrate 10 sideis formed, for example from a silicon oxide film having a thickness ofapproximately 1-2 μm. The lower electrode film 60 is formed from ametallic film having a thickness, for example, of approximately 0.2 μm.In the present embodiment, the lower electrode film 60 functions as acommon electrode for the multiple piezoelectric elements 20 arrangedbetween the flow path forming substrate 10 and the reservoir formingsubstrate 20.

On the upper surface side (+Z side in FIG. 17) of the oscillation plate400 is arranged the piezoelectric element 300 forming the oscillationplate 400. The piezoelectric element 300 is composed to laminate,chronologically from the lower electrode film 60 side, the piezoelectricbody film 70 and the upper electrode film 80. The piezoelectric bodyfilm 70 is formed, for example, from a PZT film having a thickness ofapproximately 1 μm. The upper piezoelectric film 80 is formed, forexample, from a metallic film having a thickness of approximately 0.1μm.

The piezoelectric element 300, in addition to the piezoelectric bodyfilm 70 and the upper electrode film 80, it may also include a lowerelectrode film 60. The lower electrode film 60 on the one hand iscomposed as the piezoelectric element 300, and even functions as theoscillation plate 400. In the present embodiment, the flexible film 50and the lower electrode film 60 adopt a structure which functions as theoscillation plate 400. However, even by eliminating the flexible film50, the lower electrode film 60 may function jointly as the flexiblefilm 50.

The piezoelectric element 300 (piezoelectric body film 70 and the upperelectrode film 80) are multiply provided so as to correspond to themultiple nozzle apertures 15 and pressurizing chambers 12. In thepresent embodiment, a group of piezoelectric elements 300 is provided inmultiple rows in the direction of the Y-axis so as to respectivelycorrespond to the aperture 15 composing the first nozzle aperture group15A referred to as the first piezoelectric element group, and the groupof piezoelectric elements 300 provided in multiple rows in the Y-axisdirection so as to respectively correspond to the nozzle aperture 15composing the second nozzle aperture group is referred to as the secondpiezoelectric element group. Furthermore, the group of piezoelectricelements 300 corresponding to the third nozzle aperture group isreferred to as the third piezoelectric element group, the group ofpiezoelectric elements 300 corresponding to the fourth nozzle aperturegroup is referred to as the fourth piezoelectric element group and thefirst piezoelectric element group and the second piezoelectric elementgroup are arranged in rows in the X-axis direction, and in the samemanner, the third piezoelectric element group and the fourthpiezoelectric element group are arranged in rows in the X-axisdirection.

On the upper surface side (+Z side in FIG. 17) of the flow path formingsubstrate 10 is arranged the reservoir forming substrate (protectivesubstrate, second member) 20 so as to cover the piezoelectric element300. Since the reservoir forming substrate 20 is a member which, inaddition to forming the flow path forming substrate 10, forms the liquiddroplet ejection head 1, and as its structural material, desirably makesuse of a rigid material which has a thermal swell ratio which is roughlythe same as that of the flow path forming substrate 10, in the case ofthe present embodiment, since the flow path forming substrate 10 isformed from silicon, optimal use can be made of a silicon single crystalsubstrate of the same material. Since the silicon substrate can easilyexecute processing with a high degree of precision through anisotropicetching, there is the advantage that a piezoelectric element support 24can be easily formed, as described hereafter. As with the flow pathforming substrate 10, it is possible to compose the reservoir formingsubstrate 20 using glass or ceramic material or the like, as with theflow path forming substrate 10.

The reservoir forming substrate 20 is provided with the seal 23 whichtightly seals the piezoelectric element 300. In the case of the presentembodiment, the part which seals the first piezoelectric element groupis the first seal 23A, and the part which seals the second piezoelectricelement group is the second seal 23B. In the same manner, the part whichseals the third piezoelectric element group is the third seal, and thepart which seals the fourth piezoelectric element group is the fourthseal. The seal 23 is provided with a piezoelectric element support(element support) 24 formed from an indentation of a flat visuallyabbreviated rectangle which extends vertically from the paper surface ofFIG. 17. The piezoelectric element support 24, in addition to assuring aspace so as not infringe the movement of the piezoelectric element 300on the periphery of the piezoelectric element 300, has the function oftightly sealing the space. The piezoelectric element support 24 isdimensioned such that it can seal at least the piezoelectric body film70 of the piezoelectric element 300. Furthermore, the piezoelectricelement support 24 may also be partitioned for multiple piezoelectricelements 300.

In this manner, the reservoir forming substrate 20 functions as aprotective substrate which seals the piezoelectric element 300 from theoutside environment. By sealing the piezoelectric element 300 with thereservoir forming substrate 20, the characteristic deterioration of thepiezoelectric element 300 caused by water entering from the outside andthe like can be prevented. Furthermore, in the present embodiment, onlythe inside of the piezoelectric element support 24 is sealed. However,the inside of the piezoelectric element support 24 can be protected withlow humidity by drawing an internal vacuum, or providing an environmentfilled with nitrogen or argon or the like, by which structure,deterioration of the piezoelectric element 300 can be effectivelyprevented.

The groove 20 a which penetrates the reservoir forming substrate 20 isprovided between the first seal 23A and the second seal 23B of thereservoir forming substrate 20. Through the groove 20 a, the uppersurface of the flow path forming substrate 10 is exposed to the outside,and a step difference is provided from the upper surface of the exposedflow path forming substrate 10 to the upper surface of the seal 23 ofthe reservoir forming substrate 20.

The side surface 20 b of the groove 20 a of the reservoir formingsubstrate 20 is an inclined surface. In particular, the reservoirforming substrate 20 is composed of a silicon substrate having a <1, 0,0> orientation, and if wet etching is accomplished of the siliconsubstrate with an alkali solution of KOH and the like, the side surface20 b of the groove 20 a can be given an inclined surface ofapproximately 54° through differences in the etching rate of each of thesurface directions.

On the end of the groove 20 a side of the upper surface of the reservoirforming substrate 20 is formed a second wiring 234, and on the end ofthe groove 20 a side of the lower surface of the reservoir formingsubstrate 20 is formed a third wiring 236. Furthermore, from the end ofthe groove 20 a side of the second wiring to 234 to the end of thegroove 20 a side of the third wiring 236 is formed a fourth wiring 235on the side surface of the reservoir forming substrate 20. Moreover,since the side surface of the reservoir forming substrate is inclined,in comparison to when the side surface is a vertical surface, the thirdwiring 35 can be easily formed. Moreover, in FIG. 17, there is acoupling between each wiring; however, a gap may be provided betweeneach wiring of from several μm to 10 μm. Furthermore, the second wiring234, the third wiring 236 and the fourth wiring 235 may be formed withthe same number of wires as a first wiring 237 described hereafter, andpositionally arranged in the same Y direction as the first wiring 237.

The second wiring 234, the third wiring 236, and the fourth wiring 235are desirably composed of a resin material mixed with a catalyst.Specifically, they should be composed of photosensitive a resin materialin which minute particles of Pd (palladium) have been dispersed. In thisinstance, the second wiring 234, the third wiring 236 and the fourthwiring 235 can be formed by means of only photolithography. In otherwords, by coating the resin material on the upper surface and on theside surface of the reservoir forming substrate 20, and accomplishingexposure and development, patterning can be accomplished on the secondwiring 234 and the fourth wiring 235. Furthermore, if the resin materialis coated on the lower surface of the reservoir forming substrate 20,patterning can be accomplished on the third wiring 236 by means ofexposure and development.

Moreover, the second wiring 234, the third wiring 236 and the fourthwiring 235 may be formed of a metallic material of Al or Ni—Cr, Cu, Ni,Au and Ag and the like. However, in patterning the metallic material, itis necessary for etching to be accomplished in which a resist is used asa mask, complicating the manufacturing process. In this regard, ifcomposed of a photosensitive resin material mixed with a catalyst,patterning can be accomplished of the second wiring 234, and the fourthwiring 235 by means of only photolithography, simplifying themanufacturing process.

Moreover, it is also possible for the second wiring 234, the thirdwiring 236 and the fourth wiring 235 to be structured of a metallicmaterial of Al or Ni—Cr, Cu, Ni, Au, Ag and the like. However, inpatterning the metallic material, it is necessary for etching to beaccomplished using the resist as a mask, complicating the manufacturingprocess. Relative to this, according to construction in which thephotosensitive resin material is mixed with a catalyst, it is possiblefor the second wiring 234 and the fourth wiring 235 to be patterned byonly photolithography, simplifying the manufacturing process.

On the upper surface side (+Z side in FIG. 17) of the reservoir formingsubstrate 20, the semiconductor element 200 is arranged facing down. Thesemiconductor element 200 is constructed, for example, to include asemiconductor integrated circuit (IC) which includes a circuit substrateor a drive circuit. As shown in FIG. 15, in the present embodiment, 4semiconductor elements 200A to 200D are arranged in order to drive thefirst through fourth piezoelectric elements.

Furthermore, in the peripheral border of the lower surface side (−Zside) of the semiconductor elements 200, are arranged multipleconnection terminals 44, composed of a metallic material of Al or Ni-Cr, Cu, Ni, Au, and Ag and the like. On the end of the-X side of thesemiconductor elements 200A the same number of connection elements 44are provided as in the second wiring 234 for use in providing anelectrical connection with the piezoelectric elements, arranged in rowsat the same pitch as the second wiring 234. Furthermore, on the end ofthe +X side of the semiconductor elements 200A is formed an electricalconnection 44 for use in electrically connecting an external controller.

In the center of the lower surface side (−Z side) of the semiconductorelement 200 shown in FIG. 17 is arranged the adhesive material 42 formedfrom a thermoplastic resin of polyimide and the like. By heating thesemiconductor element 200 and applying pressure to the reservoir formingsubstrate 20, the semiconductor element 200 is adhered to the uppersurface of the reservoir forming substrate 20. In this instance, byadjusting the amount of the adhesive arranged on the lower surface ofthe semiconductor element 200, and the heat/pressure amount applied whenadhering, a gap is formed of approximately several μm-10 μm between theconnection terminal 44 and the second wiring 234.

In this manner, a gap is formed between the connection element 44 andthe second wiring 234. Furthermore, there are also instances in which agap of from several μm-μm is formed between each wiring, and there is aparticularly great possibility that the gap formed between the fourthwiring 235 and the third wiring 236 will be joined at an acute angle.Furthermore, the resin material mixed with a catalyst composing eachwiring is composed of an electrical insulation material. Furthermore, inthe above state, the semiconductor element 200 and the piezoelectricelement 300 are not electrically connected.

Therefore, plating 246 is provided on the surface of the first-thirdwiring and the connection terminal. Specifically, plating 244 a isprovided on the surface of the connection terminal 44, plating 234 a isprovided on the surface of the second wiring 234, plating 235 isprovided on the surface of the fourth wiring 235, and plating 236 isprovided on the surface of the third wiring 236, respectively. With eachof the wirings composed of a resin material mixed with a catalyst,plating is provided relative to the catalyst. The plating 246 iscomposed of a metallic material of Cu or Ni, and Au and the like.Plating of different materials may also be provided on the surface ofeach wiring and connection terminal.

FIG. 18 as an explanatory diagram of the mounting structure of thesemiconductor element according to the fourth embodiment, and is anenlarged diagram of part B of FIG. 17. As shown in FIG. 18, plating 244a is provided on the surface of the connection terminal 44 of thesemiconductor element 200. The plating 234 a is provided on the surfaceof the second wiring 234. By combining the grown plating 244 a and 234a, the connection terminal 44 and the second wiring 234 are electricallyconnected, mounting the semiconductor element 200. In the same manner,the plating 234 a produced/grown on the surface of the second wiring 234shown in FIG. 17 is combined with the plating 235 a, electricallyconnecting the second wiring 234 and the fourth wiring 235. Furthermore,the plating 235 a produced/grown on the surface of the fourth wiring 235is combined with the plating 236 a on the surface of the third wiring236, electrically connecting the fourth wiring 235 and the third wiring236, by which the semiconductor element and the third wiring 236 areelectrically connected.

Furthermore to extending the second wiring 234 to a position facing theconnection terminal 44 of the semiconductor elements 200, a conductiveprotrusion may also be formed on the surface of the connection element44, facing the second wiring 234. The conductive protrusion is formed toa height of from several μm-10 μm by means of a metallic material of Alor Ni—Cr, Cu, Ni, Au, and Ag and the like. By pressurizing thesemiconductor element 200 to the reservoir forming substrate 20 so thatthe end of the conductive protrusion makes contact with the secondwiring 234, the semiconductor element 200 is adhered by the adhesive 42.A slight gap may also exist between the end of the conductive protrusionand the second wiring 234. According to such a construction, platingprovided on the conductive protrusion and the second wiring 234 can beassuredly combined, making possible a positive electrical connectionbetween the connection terminal 44 of the semiconductor element 200 andthe second wiring 234, enabling improved reliability of the electricalconnection.

The end of the upper electrode film 80 composing the piezoelectricelement 300 formed on the flow path forming substrate 10 extends to thegroove 20 a side of the piezoelectric element support 24 in thereservoir forming substrate 20, thereby composing the first wiring 237.Moreover, the first wiring 237 may be extended to the upper surface ofthe flow path forming substrate exposed through the groove 20 a. Thefirst wiring 237 is composed of Al or Ni—Cr, Cu, Ni, Au, and Ag and thelike. However, a structure is also possible which, in the same manner asdescribed for the second to fourth wiring 234-236, may be composed of aphotosensitive resin material mixed with a catalyst. Moreover, if thelower electrode film 60 is arranged in an abbreviated beta state on theflow path forming substrate 10, an insulation film 600 is arranged toprevent short-circuiting between both the lower electrode film 60 andthe first wiring 237. Furthermore, in lieu of extending the upperelectrode film 80 in its existent state, electrode wiring may also beelectrically connected to the upper electrode film 80 and formed on theflow path forming substrate 10, and the electrode wiring extended to theend of the groove 20 a side of the piezoelectric element support 24,composing the first wiring 237.

The plating 236 a provided on the third wiring 236 of the reservoirforming substrate 20 and the first wiring 237 of the flow path formingsubstrate 10 are electrically connected. An electrical connection isrealized by arranging an anisotropic conductive film (ACF) 500 betweenthe two. The anisotropic conductive film 500 is formed by dispersingconductive particles in a heat hardened resin. By dispersing theconductive particles between the plating 236 a of the reservoir formingsubstrate 20 and the first wiring 237 of the flow path forming substrate10, the two can be electrically connected without short-circuitingclosely proximate wiring, thereby mounting the flow path formingsubstrate 10 and the reservoir forming substrate 20, electricallyconnecting the piezoelectric element 300 formed on the flow path formingsubstrate 10 and the semiconductor element 200 mounted on the reservoirforming substrate 20.

In ejecting liquid droplets of functional liquid from the liquid dropletejection head 1 shown in FIG. 17, an un-shown external functional liquidsupply device connected to the functional liquid aperture 25 is drivenby an external controller (omitted from the drawing) connected to theliquid droplet ejection head 1. After supplying the reservoir 100 withthe functional liquid sent from the external functional liquid supplydevice, through the functional liquid introduction aperture 25, a flowpath which reaches the nozzle aperture 15 is achieved within the liquiddroplet ejection head 1.

Furthermore, an external controller transmits a driving power orinstruction signal to the semiconductor element 200 mounted on thereservoir forming substrate 20, through a flexible substrate (un-shownin the drawing). The semiconductor element 200 which receives theinstruction signal transmits a drive signal to each piezoelectricelement 300 based on the instruction from the external controller.Voltage is applied to the piezoelectric body film 70 supported by thelower electrode film 60 and the upper electrode film 80, producing avariation between the lower electrode film 60 and the flexible film 50closely proximate to the piezoelectric electric film 70, by which thecapacity of each pressurizing chamber 12 is changed, increasing theinternal pressure, and ejecting liquid droplets from the nozzle aperture15.

An explanation is provided of the construction method of the liquiddroplet ejection head, with reference to the flowchart drawing of FIG.19 and the cross-sectional process drawings of FIGS. 20A to 20G.

First of all, an explanation is provided of a summary of theconstruction process of the liquid droplet ejection head, with referenceto FIGS. 19 and 17.

In constructing the liquid droplet ejection head, a laminated layer ofthe flexible film 50 and the lower electrode from 60 is formed on theflow path forming substrate 10, prior to etching processing. Next, thepiezoelectric element 300 is formed (in step SA1) by pattern forming thepiezoelectric body film 70 and the upper electrode film 80 on the lowerelectrode film 60.

The reservoir forming substrate 20 is created in parallel with step SA.First of all, the groove 20 a, or piezoelectric element support 24,introduction path 26, and reservoir portion 21 are formed (in step SA2)by executing anisotropic etching on the silicon single crystalsubstrate. Next, the second wiring 234 is formed on the upper surface ofthe reservoir forming substrate 20, the fourth wiring 235 is formed onthe side surface, and the third wiring 236 is formed on the lowersurface (in step SA3). Furthermore, the semiconductor element 200 isadhered (in step SA4) to the upper surface of the reservoir formingsubstrate 20. Plating is provided on the second to fourth wiring as wellas on the connection terminal of the semiconductor element, conductivelyconnecting (in step SA5) the semiconductor element 200 and the thirdwiring 236.

Next, in a position to cover the piezoelectric element 300 of the flowpath forming substrate 10 which has passed step SA1, the reservoirforming substrate 20 which has passed step SA5 is positionally alignedand fixed (in step SA6). In this instance, the periphery of thesemiconductor element 200 shown in FIG. 20F is sealed (in step SA7) witha resin 201, as shown in FIG. 20F. Subsequently, as shown in FIG. 17,the pressurizing chamber 12, or supply path 14, and coupler 13 and thelike are created (in step SA8) by executing anisotropic etching on theflow path forming substrate 10 formed from a silicon single crystalsubstrate.

By means of the above process, manufacture can be accomplished of thesemiconductor ejection head 1 on which is mounted the semiconductorelement 200.

A detailed description of the manufacturing processes (SA2 and SA3) ofthe reservoir forming substrate, the mounting processes (SA4 and SA5) ofthe semiconductor element, and the mounting process (SA6) of thereservoir forming substrate are explained hereafter, with reference toFIGS. 20A to 20G. Each of the drawings shown in FIGS. 20A to 20G arediagrams corresponding to an outline cross-sectional structure along theline A-A of FIG. 15.

First of all, as shown in FIG. 20A, the center of the upper surface (+Zside surface) of the silicon single crystal substrate 920 is removed bymeans of etching, thereby forming the groove 20 a. Specifically, thesurface of the silicon single crystal substrate 920 is formed into anoxidized silicon film by thermal oxidation. Next, a resist is coated onthe surface of the silicon single crystal substrate 920, and a resistaperture is formed on the groove 20 a which should be formed byphotolithography. Next, the resist aperture is processed with fluoricacid, forming an aperture of silicon oxide film. Next, the siliconsingle crystal substrate 920 is submerged in an aqueous solution of 35%wt potassium hydroxide (KOH), and anisotropic etching is performed onthe silicon single crystal substrate 920 exposed from the aperture ofthe silicon oxide film. Since the silicon oxide film functions as anetching stopper, etching is suspended at the place in which the siliconsingle crystal substrate 920 penetrates. Upon completion of etching, thesurface of the silicon single crystal substrate 920 is re-subjected tothermal oxidation, forming a silicon oxide film.

The reservoir portion 21 and the piezoelectric element support 24 areformed by means of etching in the same manner.

Next, as shown in FIG. 20B, the second wiring 234 is formed on the uppersurface of the silicon single crystal substrate 920, and the fourthwiring 235 is formed on the side surface of the groove 20 a.Specifically, first of all, on the upper surface of the silicon singlecrystal substrate 920 and the side surface 20 b of the groove 20 a aliquid form of resin material mixed with a catalyst is coated by a spincoating method or a spray coating method. Next, the exposure anddevelopment of the resin material is accomplished through a mask onwhich the pattern of the second wiring 234 and the fourth wiring 235have been drawn, by which the second wiring 234 on the upper surface ofthe silicon single crystal substrate 920 is patterned, and the fourthwiring 235 is patterned on the side surface.

Next by the same method as that referred to above, the third wiring 236is formed on the lower surface of the silicon single crystal substrate920. Specifically, first of all, a coating of the liquid form of a resinmaterial mixed with a catalyst is applied to the lower surface of thesilicon single crystal substrate 920 by a spin coating method or a spraycoating method. Next, the resin material is exposed and developedthrough a mask on which the third wiring 236 pattern is drawn, therebypatterning the third wiring 236 on the lower surface of the siliconsingle crystal substrate 920.

Moreover, in the case of composing each wiring with a metallic material,a metallic film is formed by means of sputtering, and patterning isaccomplished by etching through a resist mask. Furthermore, by means ofthe sputtering method or the ink jet method accomplished through a Simask, drawing may be accomplished directly onto the second wiring 234,thereby forming the reservoir forming substrate 20.

Next, as shown in FIG. 20C, the semiconductor element 200 is directlyadhered to the upper surface of the reservoir forming substrate 20.Specifically, first of all, the adhesive material 42 formed from athermal elastic resin material is coated on the center of the lowersurface of the semiconductor element 200. Next, the connection terminal44 of the semiconductor element 200 is positionally aligned with thesecond wiring 234 of the reservoir forming substrate 20, thesemiconductor element 200 is heated, and pressure is applied relative tothe reservoir forming substrate 20. In this instance, by adjusting theamount of coated adhesive and the amount of heat/pressure applied whenadhering, a gap of roughly from several μm to 10 μm is establishedbetween the connection terminal 44 and the second wiring 234.Subsequently, by cooling the entire body and hardening the adhesive 42,the semiconductor element 200 is adhered to the upper surface of thereservoir forming substrate 20.

Next, as shown in FIG. 20D, the plating 246 is provided on the surfaceof the second wiring 234, the third wiring 236, the fourth wiring 235,and the connection terminal 44. Specifically, non-electrolytic platingis accomplished by the following process.

First of all, with the objective of improving the wettability of thesurface of each wiring and connection terminal, and removal of residue,immersion is accomplished for from one to five minutes in an aqueoussolution including 0.01-0.1 percent fluoric acid, and 0.01-1 percentsulfuric acid. Or immersion may also be accomplished for from 1 to 10minutes in an alkali base aqueous solution of 0.1-10 percent sodiumhydroxide.

Next, immersion is accomplished for from one second to five minutes inan alkali aqueous solution of a sodium hydroxide base having a pH offrom 9 to 13, while heating at a temperature of from 20-60° C., and theoutside film surface is removed. Or immersion may be accomplished forfrom one second to five minutes in an acidic aqueous solution of 5-30percent nitric acid as a base, with a pH of from 1-3, while heating atfrom 20-60° C.

Next, immersion is accomplished for from one second-two minutes in azincate solution having a pH of from 11 to 13, which includes ZnO, inwhich Zn is substituted on the surface of each wiring and connectionterminal. Next, immersion is accomplished for from 1-60 seconds in a5-30 percent nitric acid aqueous solution, and the Zn is peeled off. Byre-immersing for from one second to two minutes in a zincate solution,minute Zn particles are provided on the surface of each wiring andconnection terminal.

Next, Ni plating is provided through immersion in a non-electrolytic Niplating solution. This plating is provided to a height of 2-30 μm.Furthermore the plating solution is a solution in which use is made ofhypo phosphoric acid as the reducing agent, with a pH of 4 to 5 and asolution temperature of 80 to 95° C. Owing to the hypo phosphoric acid,phosphorus is co-provided.

Furthermore, Au may be substituted on the Ni surface by immersion in asubstitute Au plating solution. The Au is formed to a height of 0.05μm-0.3 μm. Furthermore the Au solution is a cyan free type, with a pH of6 to 8, and a solution temperature of 50-80° C., with immersion beingaccomplished for from one to 30 minutes.

In this manner, Ni or Ni—Au plating is provided on the surface of eachwiring and connection terminal. Furthermore, Au plating may be executedon the Ni—Au wiring. Even if each wiring beneath the plating is thin,the electrical resistance can be reduced by applying the plating.

Wash processing is accomplished between each chemical process. As a washbath, use may be made of an overflow structure or a QDR mechanism, withN₂ bubbling taking place from the bottommost surface. As bubblingmethods, there is the N₂ expulsion method from a hole formed in a resintube, and a method for expelling N₂ through a sinter formed body. Bythis means, an adequate and effective rinse can be accomplished in ashort time.

By means of the above processes, as shown in FIG. 18, the plating 244 ais provided on the surface of the connection terminal 44 of thesemiconductor element 200, and the plating 234 a is provided on thesurface of the second wiring 234. By growing both of these until theplating 244 a and plating 234 a mutually combine, the connectionterminal 44 and the second wiring 234 are electrically insulated. In thesame manner, by growing each plating until the plating 234 a provided onthe surface of the second wiring 234 shown in FIG. 17, the plating 235 aprovided on the surface of the fourth wiring 235 and the plating 236 aprovided on the surface of the third wiring 236 combine, the secondwiring 234, the fourth wiring 235 and the third wiring 236 areelectrically connected, by which the semiconductor element 200 and thethird wiring 236 are electrically connected.

Next, as shown in FIG. 20E, the reservoir forming substrate 20 ismounted on the flow path forming substrate 10. In other words, theplating 236 a provided on the surface of the third wiring 236 in thereservoir forming substrate 20, and the first wiring 237 formed on theflow path forming substrate 10 are electrically connected, and bothplates are mechanically connected. Specifically, in addition toarranging an anisotropic conductive film 500 between the plating 236 aand the first wiring 237, forming an electrical connection, the heathardened resin 501 is coated on the mechanical connector. The reservoirforming substrate 20 is heated, and pressed facing the flow path formingsubstrate 10, by which means, in addition to an electrical connectionbeing established between the plating 236 a and the first wiring 237,the heat hardened adhesive 501 is hardened, mechanically connecting bothsubstrates.

Next, as shown in FIG. 20F, the semiconductor element 200 is sealed, thecreative process of the pressurizing chamber 12 and the like of the flowpath forming substrate 10 being explained hereafter. Furthermore to theflow path forming substrate, both the reservoir forming substrate 20 andthe semiconductor element 200 are immersed in an etching liquid. Thesemiconductor element 200 is sealed in order to protect thesemiconductor element 200 from the etching liquid. As the seal, it isdesirable to adopt a resin material 201 of heat hardened resin and thelike. Specifically, the fixed reservoir forming substrate 20 and theflow path forming substrate 10 are arranged in a mold, and the resinmaterial 201 in the periphery of the semiconductor element 200 isdesirably an emission mold type. If the semiconductor element 200 issealed in this manner, following the completion of the liquid dropletejection head as well, the semiconductor element 200 can be protectedfrom deleterious environmental conditions of light and the like.However, if there are no problems with the environmental conditions, thesealing resin may be removed following the completion of the liquiddroplet ejection head.

Next, as shown in FIG. 20G, by executing anisotropic etching on the flowpath forming substrate 10 formed from a silicon single crystalsubstrate, a pressurizing chamber 12 is created. The specific method ofthis etching is the same as the etching method of the reservoir formingsubstrate 20. Subsequently, the compliance substrate 30 is connected tothe reservoir forming substrate 20, and the nozzle substrate 16 isconnected to the flow path forming substrate 10. After creating thepressurizing chamber 12, it may be connected to the reservoir formingsubstrate 20 as well.

The liquid droplet ejection had of the present embodiment is formedaccording to the above.

As explained in detail above, the liquid droplet ejection head 1 of thepresent embodiment is formed from the electrical connection of theconnection terminal 44 of the semiconductor element 200, the secondwiring 234 formed on the upper surface of the reservoir formingsubstrate 20, the third wiring 235 formed on the lower surface, and thefourth wiring 236 formed on the side surface 20 b are conductivelyconnected by plating 246 provided on the surface of each wiring andconnection element 44, and by further provided plating 246, a firstwiring 237 conductively connected to the piezoelectric element 300 ofthe path forming substrate 10 is conductively connected.

According to such a structure, in the case of connecting a semiconductorelement 200 and the first wiring 237 by means of wire bonding, there isno need to provide a wire guide space. Owing to this, in accompanimentwith the narrow pitching of the nozzle aperture 15, even if the firstwiring 237 is made to be a narrow pitch, the electrical connection withthe first wiring 237 is assured, and the semiconductor element 200 canbe mounted. Other than that, in comparison with mounting accomplished bymeans of conventional wire bonding, mounting is possible with a shortTAT, at low-cost, and with high yield.

Furthermore, even if there is positional slippage or a gap between theconnection terminal 44 and the wiring 234, or mutually between thewiring, plating 246 is provided, and by growing or combining, anelectrical connection can be assured. Furthermore, simultaneouslyexecuting mounting of the semiconductor element 200 and theestablishment of the electrical connection of each wiring is possible,simplifying the manufacturing process. Furthermore, even if each wiringincluding subterranean wiring is formed to be thin, electricalresistance can be reduced by the coating of the plating 246.

High precision is required in the piezoelectric element 300 formed inthe flow path forming substrate 10. However, if the piezoelectricelement 300 is immersed in plating liquid, migration occurs with the Naincluded in the plating liquid, resulting in reduced electricalreliability. If the piezoelectric element is sealed with resin toprotect it from the plating liquid, the manufacturing process becomescomplex.

In this regard, in the present embodiment, to the extent that theplating 246 is only educed on the reservoir forming substrate 20, thereis no need for the piezoelectric element 300 formed on the flowpathforming substrate 10 to be immersed in the plating liquid. Furthermore,it is possible to avoid the influence of plating processing on thepiezoelectric element 300 requiring a high degree of precision, and theelectrical reliability of the liquid droplet ejection head 1 can beimproved. Furthermore, since the flowpath forming substrate 10 is formedin the same manner as technology for performing wire bonding, there isno need to re-design the flowpath forming substrate 10, or to change themanufacturing process. Furthermore, manufacturing costs can be reduced.

According to the present embodiment, a liquid droplet ejection head 1 inwhich the nozzle aperture 15 is given a narrow pitch is possible, and ifthe device is accomplished using the applied liquid droplet ejectionhead 1, refinement and minuteness of the device can be realized.

Furthermore, according to the mounting construction of the presentembodiment, since the wiring 237 of the step difference lower part andthe semiconductor element 200 of the step difference upper part can beassuredly electrically connected, not only the liquid droplet ejectionhead, but other devices may also be mounted through a step difference,enabling broad application relative to electronic devices, transportdevices and printing devices and the like.

Fifth Embodiment

An explanation of the fifth embodiment the liquid droplet ejection headaccording to the present invention is provided hereafter, with referenceto FIGS. 21A to 21C.

FIG. 21A is an explanatory diagram of a liquid droplet ejection headaccording to the fifth embodiment of the present invention.

FIG. 21A is an enlarged diagram corresponding to part C. Given the pointthat the liquid droplet ejection head of the fifth embodiment shown inFIG. 21A is composed such that the side surface of the reservoir formingsubstrate 20 is composed of multiple inclined surfaces, it differs fromthe fourth embodiment composed of 1 inclined surface. A detailedexplanation is omitted concerning components, the construction of whichis the same as that of the fourth embodiment.

With the liquid droplet ejection head of the fifth embodiment shown inFIG. 21A, the side surface 20 b of the groove 20 a formed in thereservoir forming substrate 20 is composed of multiple inclinedsurfaces. In other words, a first inclined surface 110 facing the upperside is arranged on the upper side of the reservoir forming substrate20, and a second inclined surface 120 facing the lower side is arrangedon the lower surface of the reservoir forming substrate 20. Moreover,the reservoir forming substrate 20 is composed of the silicon substratehaving a <1, 0, 0> orientation, and by wet etching the silicon substratewith an alkali solution of KOH and the like, then either the firstinclined surface 110 and the second inclined surface 120 can be given aninclined surface of approximately 54°. A fourth wiring 235A is formed onthe surface of the first inclined surface 110, and a fourth wiring 235Bis formed on the surface of the second inclined surface 120.

FIG. 21B is a first deformation example of the liquid droplet ejectionhead of the fifth embodiment. With the first deformation example thefirst inclined surface 110 facing the upper side is composed of multipleinclined surfaces of different angles (moderate inclined surface 111 andsteep inclined surface 112), wherein each inclined surface 111 and 112is arranged on the upper side of the reservoir forming substrate 20.Furthermore, the second inclined surface 120 facing the lower side isalso composed of multiple inclined surfaces of different angles(moderate inclined surface 121 and steep inclined surface 122), and eachinclined surface 121 and 122 is arranged on the lower surface of thereservoir forming substrate 20. Each inclined surface 121,122 isarranged so that the inside angle of the closely proximate inclinedsurface becomes 90° or greater, and so that the upper surface and thelower surface of the reservoir forming substrate 20 are combined in anobtuse angle. The fourth wiring 235 A is formed on the surface of thefirst inclined surface 110. The fourth wiring 235B is formed on thesurface of the second inclined surface 120.

FIG. 21C is a second deformation example of a liquid droplet ejectionhead according to the fifth embodiment. With the second deformationexample, the upper surface and the lower surface of the reservoirforming substrate 20 are joined by a curved surface 130 which has thecross-sectional surface of a semi-circular state. In this case as well,the first inclined surface 110 facing the upper side is arranged on theupper side of the reservoir forming substrate 20, and the secondinclined surface 120 facing the lower side is arranged on the lowersurface of the reservoir forming substrate 20. Third wiring 135 isformed on the curved surface 130.

FIGS. 22A to 22D is a manufacturing process diagram of the liquiddroplet ejection head according to the first deformation example of thefifth embodiment. In manufacturing the liquid droplet ejection head ofthe first deformation example shown in FIG. 21B, first of all, as shownin FIG. 22A, a mask 118 is formed on the upper surface of the reservoirforming substrate 20, and a mask 128 is formed on the lower surface.Also, in the same manner as in the fourth embodiment, wet etching isperformed relative to the reservoir forming substrate 20. Wet etching isaccomplished with time control, and a moderate inclined surface 111 isformed continuous to the upper surface of the reservoir formingsubstrate 20, and is completed at the point of time in which themoderate inclined surface 121 is formed continuous to the lower surface.In this manner, it is possible to form a reservoir forming substrate 20provided with an inclined surface of approximately 54° such as is shownin FIG. 21A.

Next, as shown in FIG. 22B, a new mask 119 is formed applying a moderateinclined surface 111 from the upper surface of the reservoir formingsubstrate 20, and a new mask 129 is formed with a moderate inclinedsurface 121 from the lower surface, with the re-accomplishment of thewet etching referred to earlier. This wet etching is also performed withtime control management, a steep inclined surface 112 b formedcontinuous to the moderate inclined surface 111 of the upper side, andcompleted with the formation of a steep inclined surface 122, formedcontinuous to the moderate inclined surface 121 of the lower side. Bymeans of the above, the reservoir forming substrate 20 is formed as thefirst deformation example shown in FIG. 21B.

Next, as shown in FIG. 22C, the second wiring 234 and the fourth wiring235A are formed extending to the first inclining surface 110 from theupper surface of the reservoir forming substrate 20. Specifically,coating is accomplished of a photosensitive resin mixed with a catalyst,and first of all the upper surface and side surface of the reservoirforming substrate 20 is exposed. In this instance, in positivelyexposing the side surface of the reservoir forming substrate 20 it isnecessary to adjust the focal point for the depth of exposure position.However, since the fifth embodiment is composed of the first inclinedsurface 110 in which the side surface of the reservoir forming substrate20 faces the upper side, and the second inclined surface 120 in which itfaces the lower side, along with the upper surface of the reservoirforming substrate 20, first of all it would be sufficient if only thefirst inclined surface 110 were exposed. Subsequently, in accomplishingdevelopment, the second wiring 234 and the fourth wiring 235A areformed.

Next, as shown in FIG. 22D, the third wiring 236 and the fourth wiring235B are formed extending to the second inclining surface 120 from thelower surface of the reservoir forming substrate 20. Specifically,coating is accomplished of a photosensitive resin mixed with a catalyst,and the upper surface and side surface of the reservoir formingsubstrate 20 are exposed. In this instance, along with the lower surfaceof the reservoir forming substrate 20, it is sufficient if only thesecond inclined surface 120 is exposed. Subsequently, in accomplishingdevelopment, the third wiring 236 and fourth wiring 235B are formed.

Subsequently, by passing through the same process as that of the fourthembodiment, formation is accomplished of the liquid droplet ejectionhead of the first deformation example shown in FIG. 21B.

As indicated above, with the droplet ejection head 1, the side surface20 b of when the reservoir forming substrate 20 is composed of multipleinclined surfaces, wherein the first inclined surface 110 which facesthe upper side is arranged on the upper side of the reservoir formingsubstrate 20, and the second inclined surface 120 which faces the lowerside is arranged on the lower side of the reservoir forming substrate20. According to such a construction, exposure of the side surface ofthe reservoir forming substrate 20 can be accomplished by dividing theexposure light on the side surfaces of the reservoir forming substrate20 into an upper side and a lower side. Hence, in comparison with whenthe fourth embodiment accomplishes exposure once over the entire sitesurface, adjustment of the focal point depth of the exposure device canbe easily accomplished. By this means, it is possible to reduce theequipment cost of the exposure device. Furthermore, since themanufacturing process is simplified, manufacturing costs can be reduced.Furthermore, the third wiring can be simply formed at low-cost.

Furthermore, with the liquid droplet ejection head of the fifthembodiment, the side surface 20 b of the reservoir for a substrate 20 iscomposed so that the lower surface and the upper surface of thereservoir forming substrate 20 are formed so as to combine as an obtuseangle or a curved surface. According to such a construction, eachsubterranean wiring can be formed extending to the lower surface fromthe upper surface of the reservoir forming substrate 20. Furthermore, inthe case a gap is formed between each subterranean wiring as well, theplating 246 grown from the proximate subterranean wiring can be easilycombined. Furthermore, a liquid droplet ejection head can be providedwith superior electrical reliability.

Next, an explanation is provided of an example of a liquid dropletejection device provided with the droplet ejection head 1 describedabove, with reference to FIG. 23. In this example an inkjet typerecording device provided with the described liquid droplet ejectionhead is explained.

The liquid droplet ejection head composed partially of a recording headunit equipped with a pending flow path is coupled with a cartridge andthe like, wherein it is mounted on an inkjet type recording device. Asshown in FIG. 23, to the recording head units 1A and 1B equipped with aliquid droplet ejection head, cartridges 2A and 2B composing the inksupply means are removably attached, and a carriage 3 which mounts therecording head units 1A and 1B is provided so as to be freely movable inthe axial direction of a carriage shaft 5 attached to a device main body4.

The recording head units 1A and 1B eject, for example, a black inkcomposition and a color ink composition. The driving force of a drivingmotor 6 is transmitted to the carriage 3 through multiple un-shownwheels and timing belts 7, moving the carriage 3 on which is mounted therecording head units 1A and 1B along the carriage shaft 5. In the devicemain body 4 is provided a platen 8 along the carriage shaft 5, wherein arecording sheet S including the recording medium of the paper and thelike supplied from an un-shown paper supply roller, is transported onthe platen 8. Since the jet format recording device provided with such aconstruction is provided with the described liquid droplet ejectionhead, it is a small type, but has high reliability, in a low-cost inkjetformat recording device.

In FIG. 23, is shown an inkjet type recording device as a single bodyprinter in an example of the liquid droplet ejected device of thepresent invention. However, the present invention is not limited tothis, and it is possible for it to be applied to a printer unit realizedby incorporating the subject liquid droplet ejection head. This type ofprinter unit, for example, is mounted to an input device of, forexample, a television display, or the input device of a white board andthe like, and is used to print a display or an input image from adisplay device or input device.

Furthermore, the liquid droplet ejection head can also be applied to aliquid droplet ejection to accomplish each type of device by a liquidphase method. In this embodiment, as the functional liquid ejected fromthe liquid droplet ejection head, use is made of a material used forforming a liquid crystal device for forming a liquid crystal display, ormaterial used for organic EL formation forming an organic EL display, ormaterial used for forming a wiring pattern for forming the wiringpattern of an electronic circuit, and the like. According to themanufacturing process selectively arranging the functional liquid on abase by means of a liquid droplet ejection device, since a patternarrangement is possible of a functional material without passing thephotolithography process, a liquid crystal display, or organic ELdevice, or circuit substrate can be manufactured at low-cost.

While preferred embodiments of the invention have been described andillustrated above, it should be understood that these are exemplary ofthe invention and are not to be considered as limiting. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the spirit or scope of the present invention.Accordingly, the invention is not to be considered as being limited bythe foregoing description, and is only limited by the scope of theappended claims.

What is claimed is:
 1. A manufacturing method of a device that has asemiconductor element, comprising: forming a first wiring on a firstsurface of a first member; forming a second wiring on a second surfaceof a second member so as to have a gap from a connection terminal and athird wiring on an inclined plane side surface of the second member, thesecond member disposed on the first surface of the first member, thesecond surface facing in a same direction as the first surface of thefirst member, the third wiring positionally aligned with the firstwiring and the second wiring for connecting the first wiring and thesecond wiring; disposing the semiconductor element on the first surfaceof the first member or on the second surface of the second member; andproviding plating that electrically connects the first wiring, thesecond wiring, the third wiring, and the connection terminal of thesemiconductor element, wherein the connection terminal is disposed so asto face the second wiring, and the plating is provided in the gapbetween the connection terminal and the second wiring.
 2. Amanufacturing method of a liquid droplet ejection head that ejectsliquid droplets through deformation of a driven element, comprising:forming a first wiring on a first surface of a first substrate that hasa pressurizing chamber which communicates with a nozzle aperture thatejects liquid droplets; forming a second wiring on a second surface of asecond substrate so as to have a gap from a connection terminal and athird wiring on an inclined plane side surface of the second substrate,the second substrate disposed on the first surface of the firstsubstrate, the second surface facing in a same direction as the firstsurface of the first substrate, the third wiring positionally alignedwith the first wiring and the second wiring for connecting the firstwiring and the second wiring; disposing the semiconductor element on thesecond surface of the second substrate; and providing plating thatelectrically connects the first wiring, the second wiring, the thirdwiring, and the connection terminal of the semiconductor element,wherein the connection terminal is disposed so as to face the secondwiring, and the plating is provided in the gap between the connectionterminal and the second wiring.
 3. A manufacturing method of a devicethat has a semiconductor element, comprising: forming a first wiring ona lower step surface of a stepped body, forming a second wiring on anupper step surface of the stepped body so as to have a gap from aconnection terminal, disposing the semiconductor element on a sidesurface that connects the upper step surface and the lower step surfaceof the stepped body, and providing plating that electrically connectsthe first wiring, the second wiring, and the connection terminal of thesemiconductor element, wherein the connection terminal is disposed so asto face the second wiring, and the plating is provided in the gapbetween the connection terminal and the second wiring.
 4. Amanufacturing method of a liquid droplet ejection head that ejectsliquid droplets through deformation of a driven element, comprising:forming a first wiring on a first surface of a first substrate that hasa pressurizing chamber which communicates with a nozzle aperture thatejects liquid droplets; forming a second wiring on a second surface of asecond substrate so as to have a gap from a connection terminal and athird wiring on an inclined plane side surface of the second substrate,the second substrate disposed on the first surface of the firstsubstrate, the second surface facing in a same direction as the firstsurface of the first substrate, the third wiring positionally alignedwith the first wiring and the second wiring for connecting the firstwiring and the second wiring; disposing the semiconductor element on theside surface of the second substrate; and providing plating thatelectrically connects the first wiring, the second wiring, the thirdwiring, and the connection terminal of the semiconductor element,wherein the connection terminal is disposed so as to face the thirdwiring, and the plating is provided in the gap between the connectionterminal and the third wiring.
 5. A manufacturing method of a devicethat has a semiconductor element, comprising: forming a first wiring ona first surface of a first member; forming a second wiring on a secondsurface of a second member so as to have a gap from a connectionterminal, a third wiring on a third surface of the second member, and afourth wiring on an inclined plane side surface of the second member,the third surface being opposite the second surface; disposing thesemiconductor element on the second surface of the second member;providing plating that electrically connects the second wiring, thethird wiring, the fourth wiring and the connection terminal of thesemiconductor element; and disposing the second member on the firstsurface of the first member to electrically connect the plating and thefirst wiring, wherein the connection terminal is disposed so as to facethe second wiring, and the plating is provided in the gap between theconnection terminal and the second wiring.
 6. A manufacturing method ofa liquid droplet ejection head that ejects liquid droplets throughdeformation of a driven element, comprising: forming a first wiring on afirst surface of a first substrate that has a pressurizing chamber whichcommunicates with a nozzle aperture that ejects liquid droplets; forminga second wiring on a second surface of a second substrate so as to havea gap from a connection terminal, a third wiring on a third surface ofthe second substrate, and a fourth wiring on an inclined plane sidesurface of the second substrate, the third surface being opposite thesecond surface; disposing the semiconductor element on the secondsurface of the second substrate; providing plating that electricallyconnects the second wiring, the third wiring, the fourth wiring and theconnection terminal of the semiconductor element; and disposing thesecond substrate on the first surface of the first substrate to coverthe driven element and to electrically connect the plating and the firstwiring, wherein the connection terminal is disposed so as to face thesecond wiring, and the plating is provided in the gap between theconnection terminal and the second wiring.